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Frequently Asked Questions


The button location can be moved to the right of the Send button by changing the location from 1 to 3 in the configuration file by following these instructions:

  1. Go to My Computer
  2. Click and open your “C” drive
  3. Click and open Program Files
  4. Click and open RPost
  5. Click and open RPost Office
  6. Click and open “Config.txt” file
  7. Near the bottom change the button position from 1 to 3:
    • #Button position on command bar permissible values 1-9
    • Button position:3
  8. Click “Save”
  9. Open Outlook
  10. From the Inbox, click on TOOLS > OPTIONS > REGISTERED EMAIL (tab)
  11. Press “Restore Default”
  12. Close the options section and press New.  Your button should be now on the right.

Also, other features can be turned on or off by changing True to False or False to True next to each feature.

Below are the instructions to upgrade your “Send Registered” button to have the latest features:

Step 1: Uninstall current version.

  1. Close Outlook
  2. Press Start / Control Panel
  3. Click Add/Remove programs
  4. Wait for the list to populate and remove “RPostOffice”

Step 2: Install new version

  1. Close Outlook
  2. Log on to
  3. Choose the correct Outlook software version
  4. Follow the steps to install the Registered Email button

Step 3: Choose your features

  1. Open Outlook
  2. Click on Tools / Options / Registered Email (tab)
  3. Choose the features you want turned on and off by checking or un-checking the appropriate boxes.

To Install the new version:

  1. Close Outlook
  2. Log in to and click on the email software version you have and install it by running the program and following the on-screen instructions. You do not need any account usernames and passwords.

If this does not work, click here to request a call from an RPost specialist.

With Microsoft Outlook the Registered Receipt email will be returned to you within a few hours or less.  The “(R)eceipts” folder is a sub folder of your inbox and is created once the FIRST Registered Receipt email is returned to you.  To manage this feature, please check or uncheck the option in the Registered Email tab in the Options section of Outlook


Because RPost proves delivery, content and time without any third party storing the content or transmission information, RPost attaches the data required to reconstruct and validate the original email, attachments, and transaction information in an encrypted file. The file is attached to the Registered Receipt email which is returned to the sender, ready for authentication on demand, for use in case of a dispute. That encrypted "Locked" file attached to the Registered Receipt email can sometimes cause a spam of virus filter to quarantine the Registered Receipt email or tamper with the file making the receipt fail during authentication.  If after a maximum of six hours you still do not see the Receipt folder your spam/virus program may be blocking it.  Please check your quarantine or junk mail folder at this time.
For optimal service, RPost suggests customers to “white list” RPost as a source of safe messages. RPost messages can be identified as follows:

  • The address: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • The Sender Domain:

RPost – Button missing after using it in the past

This is a step by step document that will show you how to fix the RPost tab if it disappears.

If you no longer see this “Send (R)egistered” tab when you are composing a new mail message.

Step 1: From the Outlook Inbox press “Help”

Step 2: Select “About Microsoft Office Outlook”

Step 3: Click the “Disabled Items” Button

Step 4: The disabled box will pop up and have the RPost Addin listed. You must re-enable it.  
(This is an example of a snap in. It is not the RPost snap in)

Step 5: After re-enabling the RPost Addin, “close” Outlook and Re-open it.  When a new message is composed the RPost “Send Registered” button should be present.

Possible Next Action:  If you still do not see the “Send Registered” button:

Step 1: Go to “Tools” then “Options”

Step 2: Then select the “Other Tab” and “Advanced Options…”

Step 3: Once you are in the “Advanced Options” box, select the “Add-In Manager…” button.

There is no system in the world (physical or electronic) that can tell if a letter or email has been opened 100% of the time, which is why the laws (state and federal) say you just need to prove delivery. This is similar to a FedEx® and Certified mail signature of the mail room attendant, receptionist or assistant of the receiver. The RPost system uses a variety of methods to establish the delivery status of Registered Email messages, and the ability to prove whether the message was opened depends on the technical configuration of the recipient environment. RPost can prove a message was opened in many but not all cases.


No. There is no system in the world (physical or electronic) that can tell if a package or email has been opened 100% of the time, which is why the laws say you just need to prove delivery. The RPost system uses a variety of methods to establish the delivery status of Registered Email messages, and the ability to prove whether the message was opened depends on the technical configuration of the recipient environment.  RPost can prove a message was opened in many but not all cases.

RPost Registered Email messages should not be flagged as spam or as containing a virus any more than a regular email.  In fact, through many of our partnerships, RPost is actively becoming ‘white-listed’ with many of the large corporate ISPs, Managed Service Providers and Email Service Providers. In the event that a message is rejected by a spam filter outright, the Registered Receipt email will indicate “Delivery Failure.” If a message is delivered but classified as spam by the filter, the Registered Receipt email will indicate “Delivered to Mail Server.” In this case, the Receipt enables the sender to retain proof of delivery for that email.  This is important if the sender needs evidence that they fulfilled their requirement to send a notification.

No.  RPost uses standard SMTP protocol at no risk to the security of a network.

Yes. The RPost® software and systems are unique and are covered by more than 50 patents with worldwide coverage. A list of RPost's patents covering RPost's software and systems may be found here.

The Registered Email service uses standard SMTP protocol and a proprietary process to determine if a message was delivered; what level of delivery took place, or if there was a failure due to a bad address, the receiver’s network being down or their mailbox full.  This is done fully independent of the receiver’s system being configured or not configured a certain way.  Therefore, the opted “send no acknowledgement” has no impact on the Registered Receipt email being automatically returned to the sender.

Like physical postage which charges by the number of packages and weight, a Registered Email unit is defined as one recipient address per Megabyte (MB).  For example, one Registered Email message sent to two addresses is two units (To, Cc or Bcc).  One email sent to one address with an attachment of 2 MB is two units.

  • RPost networks are designed with availability as a core objective along with security, performance and scalability.
  • The servers and networks employ both local and geographic redundancy and utilize both load balancing and failover techniques.
  • The RPost system has been accredited for sensitive and critical U.S. Government communications.

Any email user can send a Registered Email message.  The way the message is sent depends on the specific software or email service the sender uses.  Registered Email works with most other email and workflow software seamlessly.


You will automatically receive the Registered Receipt email in your email inbox approximately one hour after sending -- depending on such factors as the receivers' system, if there is a delivery failure (mailbox full, wrong address, etc.), or if there was a large number of recipients in the address field of the original email. The Registered Receipt email is the only permanent record you will receive detailing the status of your sent email,  - proof of its delivery and its content. If desired, RPost can send the sender a duplicate which can be archived in a master back-up system for future verification.

If there is ever a dispute regarding the delivery or content of the message or attachment, the receipt can be authenticated by simply forwarding it to the RPost verification address located on the receipt.  The RPost system unlocks the encrypted attachment, regenerates digital fingerprints and hashing data to prove its integrity, and sends the original back to the person who submitted the receipt for verification.  The Registered Receipt email is very durable, meaning that it can be forwarded to any disputing party and they can authenticate the receipt.  It can even be saved onto CD or keychain micro-drive and brought to an arbitrator for authentication.  In every case, the RPost system will regenerate the original email and all attachments if authentic, but otherwise deliver a notice that the email had been tampered subsequently and no longer valid where that is determined to be the case.

RPost Registered Receipt™ email are electronically sealed and tamper detectable documents and use sophisticated encryption techniques. When the Registered Receipt email is forwarded to the RPost Registration System, the RPost Digital Seal™ marks are compared to the ones that are instantly regenerated for verification. RPost receipts incorporate two forms of encryption algorithms, the SHA-1 hash and Triple DES algorithm. RPost uses encryption components which are based on open cryptographic standards - the algorithms defined by these standards are the most widely used in the world today, and are counted among the strongest available in the commercial sector. They are tested for compliance with these standards by independent laboratories, and validated by the United States Government.  In short, if the two sets of originally recorded digital fingerprints do not line up during the verification process, the system knows that something has been altered, but not the specific word, punctuation, etc. that was altered – hence, “tamper-detectable” as opposed to “tamper-proof” for unencrypted Registered Email messages.

RPost does NOT store the Registered Receipt email or your email message content or attachments.  Because RPost does not store the information on its network (to avoid possession of discoverable information) the original content has to be stored by the email sender in the form of the Registered Receipt email.

The core value of the Registered Email service resides in the Registered Receipt email, so it is important to archive these to protect the sender and the company in the event of a future event.  In general, the company can set up a separate email address like This e-mail address is being protected from spambots. You need JavaScript enabled to view it and the RPost software, company server, partner or RPost can send a copy of the receipts to that address.  The specifics depend on the user or company environment.

RPost does not keep any email messages or attachments on the RPost Registration Systems. All of the data required to reconstruct and validate the original email, attachments, and transaction information is is compressed into a file, attached to the Registered Receipt email and returned to the sender authentication-ready for use in case of a dispute. The second attachment is an HTML version of the Registered Receipt email for people who receive it in Plain Text and want to view it in their browser. The third attachment is a digital fingerprint needed to validate and re-construct the original email message in the event of a dispute. The receipt and attachments associated must remain together for verification purposes.

Coordinated Universal Time (UTC) - the new standard world time, is Greenwich Mean Time (GMT) less daylight savings. UTC uses a 24-hour system of time notation. To convert from UTC to your local time you need to add or subtract hours, based on daylight savings. For example, Eastern Standard Time subtract 5 hours from UTC, Pacific Standard Time subtract 8 hours from UTC (with daylight savings).

As long as you keep a digital copy of the Registered Receipt email in Message Format, you can use it to verify the email at anytime and as many times as necessary.

For each Registered Email message sent, RPost returns a Registered Receipt email to the sender which contains a digital snapshot of the entire email transaction in case of a subsequent dispute. This includes the ability to verify after-the-fact:

  • Proof that the email was delivered, with an official time stamps of sending and receiving.
  • Proof of the email content sent and received, including any attachments.
  • A mechanism to verify the integrity of the receipt and reconstruct the original email content and attachments.

Note: Caution users to be sure to hold on to Registered Receipt emails in electronic format (do not print and delete as this negates the strength of the Registered Receipt email).

There are four levels of delivery reported in the Registered Receipt email: The difference amongst the three "delivered" dispositions has to do with how much information RPost can elicit about the delivery to determine the status.


This might occur if there is an email address error or the receiver's mailbox is full, among other reasons.


This is the minimum requirement for a document to be deemed as legally delivered according to government definitions. When the receiver's authorized electronic agent signs the message, RPost deems it delivered. In parallel, with courier or overnight service, certified or registered mail, a document is deemed delivered when the receiver's authorized agent (i.e. mailroom clerk, receptionist) signs for the document. The E-Sign and similar acts give email transmissions equal status to paper transmissions, in most circumstances.


This means that the RPost System is certain that the email was accepted by the recipient’s agent and that agent placed that email in the recipient’s mailbox. A physical mail analogy is your assistant signing for a delivery and putting it on your desk.


This means the recipient, or a designee with access to their email, opened that email. A physical mail analogy is when you sign for a package yourself. If the RPost system can detect “Opening” with confidence after the Registered Receipt™ email is returned to the sender, then the RPost system will return a follow-on Open Receipt™ email at the point in time that the email was detected to have been opened.

It is important to note that if the Registered Receipt email does not indicate “Opening,” that does not necessarily mean the email was not “Opened”. It means the email was either not opened or the system could not determine with confidence that the email was opened. No system can determine “Opening” all of the time.

It records the Internet delivery history, the dialog between the recipient's mail server and the RPost Registration Systems.

The time it takes to receive the Registered Receipt email depends on the receiver’s system and the number of addresses included in the delivery field.  It is typically sent within an hour with a maximum of six hours.  As a placeholder, the RPost system gives the sender an immediate Acknowledgement™ email as confirmation that the sender’s Registered Email message actually left their outbound server, arrived at RPost and is in processing.  Since RPost wants to report the highest level of delivery available within a reasonable amount of time, often more time is required to glean sufficient delivery information and those operating parameters are set based upon more than seven years of delivery statistics.


Yes. Registered Email® services support any and all attachments that your email program normally allows and requires no extra steps to upload or download the attachment.

Yes. Registered Email® services support any and all attachments that your email program normally allows and requires no extra steps to upload or download the attachment.

Yes. Registered Email® messages can be sent to any valid email address, regardless of location of receiver.

Yes. Registered Email® messages can be sent to many recipients in the To, Cc and Bcc field as your email program normally allows. The sender will receive only one Delivery Receipt for all recipients that are associated with that email message and each recipient's delivery status will have a row in the Delivery Status section. Note, RPost does limit the number of recipients in an email to 100, to protect against abuse. For special volume mailing installations, contact RPost ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it ).

No. RPost does not store any email or components of any email. RPost encrypts, compresses and attaches to the Delivery Receipt all of the data needed to authenticate the Delivery Receipt, transmission information, and re-present an authenticated original email body with attachments.

No. Most common installations of Registered Email® service work by adding the light Send (R)egistered™ software add-in into your mail client (desktop email program) that routes only email that you want to be sent "Registered" through the RPost Registration Networks. The RPost System™ does not store email. There are separate server side solutions that provide an organization or its individuals the ability to send Registered Email® messages based upon the preference of the sender's organization.

No. The recipient only needs a valid email address.

There are subtle cosmetic and functional differences when using Outlook Editor versus Word Editor. These subtleties differ by version of Outlook 2000 or XP and do not impact core service functionality. For details, contact RPost ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it ) with the specific questions and the version of Outlook as well as the type of Mail Editor.

To be clear, RPost’s Registered Email® service is completely different from various email authentication systems that have been proposed by a number of email providers in an effort to produce an Internet standard for email "sender authentication". The goal with these sender authentication plans have been to increase trust for the email recipient and reduce the threat of spoofing and phishing. DKIM is an example of a proposed solution. DKIM stores public keys in DNS and digitally signs emails on a domain basis. In general, these email authentication systems provide value in allowing message recipients to view email with a greater degree of trust and hold sending domains more accountable.

By contrast, Registered Email® services protect the sender by providing a verifiable record of the email delivery and the content for the sender. Sender authentication systems do not offer such protection to the sender. In fact, the two systems complement each other rather than compete.

RPost allows the use of a company's client code accounting system to allocate costs of the Registered Email message to their clients or vendors. Insert an optional code in the Client Code field in the dialog box that pops up after you press Send (R)egistered™ to have a specific tag associated with that Registered Email receipt. The client code is transparent to the receiver of the Registered Email message.

The Acknowledgement email arrives in the sender's inbox as soon as the email has been inducted into the RPost Registration System for processing. If the Acknowledgement does not arrive within several minutes of sending the Registered Email® message, contact your IT director. In general, if you do not get an Acknowledgement email, your Registered Email® message has not reached the RPost Registration System and therefore will not be delivered. Note that in some installations, the sender can turn off the Acknowledgement email receipt.

The default Registered Email service has an email capacity of 25 MB per Registered Email message.  This can be adjusted on a per-company basis.

As soon as the RPost Registration Systems induct an email message for processing, the sender receives an Acknowledgment email returned to their inbox. The Acknowledgement email has an official time seal, which provides proof of sending as a placeholder until the Delivery Receipt arrives. It also serves to alert the sender that the email has made it out of their internal mail system, and is on its way to the intended recipient. The Acknowledgement email is similar to the receipt that the FedEx carrier gives to the sender after taking a package.


RPost does not a store a copy of the Registered Email message, so this does not apply.

Registered Email® services allow the sender to prove that they have complied with the bye law, contractual, or regulated notification provision. While using USPS first class mail, the presumption of “delivery” is evidenced where you have a record of sending; however, under the Uniform Electronic Transaction Act, email "delivery" is evidenced when the recipient's agent (their mail server) has accepted the entire data transmission. Therefore, under electronic statutes, the burden is on the sender to prove "receipt" of the email, which is one of the key features of the RPost® system.   Further, provisions of electronic law and recent court decisions underscore the fact that e-business systems require proper transaction documentation. Often there is a requirement for a reliable recordkeeping management system that can record, retrieve and authenticate electronic messages involving important business communications and transactions (both content of email and attachments, and official time sent and received). The Registered Receipt™ email is a simple, elegant solution to record retention and proof of compliance with notification requirements.

Yes, according to the U.S. Federal E-Sign laws and the state version: the Uniform Electronic Transmission Act (UETA). RPost Registered Email services comply with these laws.  With the features “Digital Seal”, “Register Reply” and “eContracting” the sender can add their signature and even allow the receiver to reply back with a signed email even though they don’t subscribe to the RPost service.

As all email users know, email addresses sometimes are not typed correctly.  If the sender mistypes an email address the Registered Receipt may say that it was delivered (if the address is valid) or there may be a delivery failure (if the address does not exist).  In both cases, the sender did not email the correct person so the email was not legally delivered.  This is similar to a mail package sent to the wrong apartment number but still signed as delivered.  It is legally meaningless.  The Registered Receipt email will indicate delivery (of failure) to this wrong address.

Yes. The Registered Email® service seamlessly plugs into virtually any email archive or compliance solution. As a rule of thumb, if your system manages email records, you can easily add Registered Email services to it.

A team of leading electronic information management attorneys conducted a thorough review of RPost's Registered Email service in 2007 and concluded that Registered Email messages provide sufficient proof as to be admissible in a United States court according to the Federal Rules of Evidence. Their findings state that the Registered Email service is able to prove to a court that a particular message was delivered, precisely when, what it said, and often even whether it was opened. In early 2008, the author of the British Standards Institute ‘Legal admissibility’ Code of Practice – BIP 0008 reviewed the RPost service and deemed that RPost’s Registered Email receipts are court admissible evidence in the United Kingdom as to their fact of delivery, as to their trusted time of delivery and as to the authenticity of their content. Further, more than 20 leading law organizations have endorsed or sponsored RPost's services, including the bars of New York City, Chicago, Los Angeles County, District of Columbia, Denver, Atlanta, Cincinnati, Cleveland, King County (Seattle-area), Clark County (Las Vegas-area), Maricopa County (Phoenix-area), Hennepin County (Minneapolis-area), Fayette County (Lexington, Kentucky-area), Westchester County (New York City region), the State of Virginia, the State of New Mexico, the State of Colorado, the State of Hawaii, the State of Utah, and Puerto Rico.   RPost is not aware of instances where Registered Email messages have or have not withstood  court challenge as customers would not report such activity in our normal course of business.

Yes. The RPost® software and systems are unique and are covered by more than 50 patents with worldwide coverage. A list of RPost's patents covering RPost's software and systems may be found here.