Email Services

There are multiple ways of sending email from APRS to an Internet user. Be aware that 3rd-party communication rules apply for your country of operation.

All examples contain the TNC2/APRS format of the packet.  However, all messages (except the ?APRSM query) msut be numbered messages (that will be acked). For clarity, the number sequence "{xxxxx" has been left off of the examples.

It is important to note that sending an email from APRS is an INTERACTIVE activity. It relies on the sending station using numbered messages, the sending station being capable of sending and receiving appropriate acks, and the sending station receiving status messages from the server. The servers are NOT capable of supporting automated stations sending emails in the blind. Stations attempting such may be blocked by the sysops to prevent abuse of their servers and of the APRS airwaves.

Also note that because the APRS<->Email gateway function is INTERACTIVE, do NOT attempt to send emails to automated email clients which may not be capable of properly processing NDRs as shown below. Do NOT use EMAIL or EMAIL-2 to check into automated responders such as certain "nets" on Winlink or automated transmission clients on Winlink. If you do, you risk being blocked from the email servers as email loops can occur.


The easiest way to send email is to send a message to EMAIL with the recipient's email address as the first "word" of the message. You may only send one line messages (67 total characters maximum).

        Send APRS message "email@address message text" to EMAIL.
        APRS Format: URCALL-10>APRS::EMAIL    :urname@urdomain.bogus This is a test.

Keith Sproul WU2Z retired the EMAIL server in 2019. It has been replaced with a javAPRSSrvr Email Gateway and has all of the features of EMAIL-2 (see below).

javAPRSSrvr Email Gateway(EMAIL-2)

javAPRSSrvr supports email via EmailGate. This server supports the EMAIL method of sending email and supports some new features outlined below. EmailGate now properly supports UTF-8 in both APRS messages and emails (see Email to APRS support below).

Currently, EMAIL and EMAIL-2 are the callsigns for the general email servers. Others exist run by other sysops. Both support delayed delivery of APRS messages. Both supports messaging to/from Winlink.

In addition to the original method of having the email address as the first word, javAPRSEmail supports callsign specific shortcuts. (All EMAIL-2 shortcuts and commands are case-insensitive; all callsign-SSIDs must be upper case.)

To create a shortcut:
        Send APRS message "shortcut email@address" to EMAIL-2
        APRS Format: URCALL-10>APRS::EMAIL-2  :me urname@urdomain.bogus

To use the "me" shortcut I defined above to send an email from any of my stations:
        Send APRS messaage "shortcut message text" to EMAIL-2
        APRS Format: URCALL-7>APRS::EMAIL-2  :me This is a test.

I can ask for a list of all my shortcuts by sending:
        Send APRS message "shortcut L" to EMAIL-2
        APRS Format: URCALL-10>APRS::EMAIL-2  :me l
This will cause an email to be sent to urname@urdomain.bogus with all of my shortcuts.

To remove the "me" shortcut, I would send
        Send APRS message "shortcut R" to EMAIL-2
        APRS Format: URCALL-10>APRS::EMAIL-2  :me r

Shortcuts are associated with the callsign so each amateur can have their own shortcuts. They can only include alpha and numeric ASCII characters (no punctuation. white space, or Unicode characters).

Email to APRS Support

Shortcuts may be used by persons on the Internet to send an APRS message to a station via email. In other words, an amateur may create a shortcut for an email address (see above) and the holder of that email address may then send emails to any of that amateur's stations. For instance, using the example above (URCALL setting a shortcut of "me" for "urname@urdomain.bogus", I could send an email to any of my stations from the urcall@urdomain.bogus email address if the email is formatted as follows:

The email must be from the email address specified in the shortcut you have defined.
The email "subject" must start with the station callsign-SSID (must be all upper case) followed by a colon and then the message text.
The email "body" must contain the text "userid:shortcut:" where "shortcut" is the assigned shortcut for the from email address. Note: The shortcut is encapsulated with colons and userid:shortcut: cannot contain spaces.

As an example, the following would be a message I would send to one of my stations (email address and shortcut is just an example, not real):

From: urname@urdomain.bogus
To: EMAIL-2 email address (determine by sending yourself an email).
Subject: URCALL-10:Testing email to APRS.
This is a test userid:me: of APRS email gateway.
Your Name URCALL

Note that this allows an amateur to control who is allowed to send them emails by restricting it to people defined within shortcuts and those people must know the proper message format.

javAPRSEmail now supports extended DSN (Delivery Status Notification) responses.  In addition to the normal error messages, the following are issued for emails that are accepted for translation to APRS:

Undelivered Message Caching

Some javAPRSSrvr email gateways support unacknowledged message caching. This support allows a valid email to APRS message that goes unacknowledged to be held until such time that the amateur is available and queries the email gateway for cached emails. If a valid email is converted to an APRS message and that message goes unacknowledged after 4 tries, the amateur radio operator may retrieve that message (and any other unacknowledged messages) by sending the word "get" to the email gateway. If multiple messages for that ham are cached, the gateway will pace the messages at a 10 second interval. An example get message would be:

        Send APRS message "get" to EMAIL-2
        APRS Format: URCALL-10>APRS::EMAIL-2  :get

EMAIL-2 supports caching for up to 24 hours. The ?APRSM query is equivalent to the get command and is supported by EMAIL-2.