Eudora is a venerable email program that many people still find easy to use, and was recommended by GreenNet before we switched to suggesting free software Thunderbird (incidentally the free/open source Eudora OSE 1.0 is based on Thunderbird). 

The specific advice & settings given below apply to GreenNet-hosted email accounts.  If your account isn't hosted with us, please check with your ISP for the correct settings to use with their servers.

You may find occasionally problems either sending, or rarely receiving, email particularly when you are away from home.  Typically Eudora just spins its yin-yang symbol for a bit and eventually shows a task error  "Could not connect to".  This is usually because providers of network connections in hotels, academic institutions and conference centres for example, want to prevent spam being sent through their network.  Therefore they have blocked the usual "port" numbers used by email programs.   This problem of not being able to connect through certain semi-public networks isn't unique to Eudora, but one traditional shortcoming of Eudora is that it does make it slightly harder to change the usual port numbers.  By the way, if you're not sure what version of Eudora you're using, just look under the "Help" menu and "About Eudora".

The first thing to check is that you can access websites, for example GreenNet webmail, which you should be able to use while Eudora is out of action. If you can't see websites or get a warning from the provider of the connection, then the connection itself is something you will need to look into before thinking about your email program. 

If you are having problems that can't be solved by changing any of the settings mentioned below, you might want to talk to whoever's responsible IT support wherever you are as they may be blocking more ports than necessary.

Sending errors not related to ports

If you get an error like "SSL Negotiation Failed" or "Server SSL Certificate Rejected" then probably Eudora is not accepting the secure certificate from the server because that certificate is too recent.  You can either try to install the correct certificate, install the root certificate, or turn off SSL security.  See sending email via SMTPS for more information.

If you get an immediate error from Eudora, within a second or two, it may be something like a password problem.  Typically Eudora will show the error "450 4.7.1.... Client host rejected: Service unavailable" or "Client host rejected: Access denied", which means the port number is fine but you are not authenticating with the correct password.  Occasionally Eudora seems to do this spontaneously, possibly because of an anti-virus program.  Just closing Eudora and re-opening, or rebooting the computer may resolve this.  If it doesn't, check "allow authentication" is on in the "sending mail" as below.

  • It can also be that some personae authenticate but others don't: click on right-most tab on the left-hand pane to bring up the various addresses, right-click on the persona you are sending as, choose "Properties", and find the oprion about "allow authentication" or "authentication allowed" and tick that, then OK.

If that still doesn't work, go to Special > Forget Passwords and when checking mail, re-enter the password (the same one as you might use for webmail).

Eudora for Windows (versions 5.1 to 7.1 inclusive)

Firstly, enabling the "Ports" category on Eudora for Windows may be useful if the basic settings are correct but there are still problems.  Here's how to do it:

  1. Close down Eudora for the time being
  2. Start Windows Explorer (either open "My Computer" or press <Windows key>+E)
  3. Navigate to My Computer > C: > Program Files > Qualcomm > Eudora (it may just be Eudora)
  4. Find the extrastuff folder in that, and navigate inside it (you could also search for it from the Start Menu if you can't find it)
  5. There should be a file called esoteric.epi.  Right-click on this file, and from the context menu choose "Copy".
  6. Go back (up) one level and go to Edit > Paste, to create a copy of esoteric.epi in the main Eudora folder
  7. Restart Eudora
  8. Go to "Tools" > "Options" and scroll down the categories to check that the "Ports" category is there.

Check the basic settings:

  1. Click on the "Sending Mail" icon in the options.
  2. What do you have in the smtp server box?  Any of "" or
    "" or "" or just blank should work (although "" is preferred).
  3. "Allow authentication" should always be on.

If you've been having problems sending and changed anything here, it's worth trying "Send Queued Messages" now.

If you're still having problems sending, try using the alternative port.  Try each of these combinations in turn in the Sending Mail category, testing after each one:

  1. Tick "Use submission port (587)" and under "Secure sockets when sending", select "Required, STARTTLS".  (If you get a certificate error, at least it means you're able to connect.  You can either just accept the certificate, or see here.)  In theory, this is the setting that should work in the largest number of locations.
  2. Untick "Use submission port (587)" and under "Secure sockets when sending", select "Never" (note that this is not secure so make sure you're not sending anything really private).
  3. Ensuring "Use submission port (587)" is still unticked, try "Required, alternate port". (This is secure, that is, encrypted).

If you are still unable to send, this is where the esoteric settings come in.  Scroll down to the bottom category of options which should be "Ports".  Select that, and under SMTP port, change "25" to "2525".  Try again.  If that still doesn't work, contact the institution or internet provider to ask about their firewall.

In the unlikely event you can send but not receive, the process is similar.  In Options, select the "Checking Mail" category.  Here try the following settings:

  1. Set "Secure Sockets when Receiving" to "Required, Alternate Port"
  2. Set "Secure Sockets when Receiving" to "Required, STARTTLS" (secure, and the preferred setting)
  3. Set "Secure Sockets when Receiving" to "Never" (not encrypted, so theoretically someone providing the connection could scan your incoming email)

If you are still unable to receive you might want to try creating a new persona, but if you were using POP, try IMAP, or vice versa.  If that doesn't work, pretty much all legitimate ports are blocked and the institution doesn't seem to want you to retrieve your email (this is an unusual case, so please do contact us if you need access to your mail some other way). 

Eudora for Mac

This is how to enable to "Ports & Protocols" category

  1. Close down Eudora for the time being
  2. In Finder, go to Applications > Eudora Application Folder.
  3. Click once on the Eudora icon, then click File > Get Info
  4. There should be a section "> Plug-ins" towards the bottom.  Open that by
    clicking on the arrow.
  5. Make sure any item marked "Esoteric Settings" is ticked.
  6. Close the Eudora Info window and restart Eudora
  7. Go to Eudora > "Preferences" and scroll down the categories to check that the "Ports & Protocols" icon is there.

Now check the basic settings:

  1. Go to Eudora > Preferences... and click on the "Sending Mail" icon
  2. What do you have in the smtp server box?  Any of "" or "" or "" or just blank should work, although "" is preferred. (If it is followed by a colon and a number, try changing that number from "587"to "2525" or vice versa, and  try sending again, or try ticking "submission port (587)")
  3. "Allow authorisation" should always be on.
  4. Scroll down the categories until you get to "SSL".  Select the relevant
    personality, and under "SSL for SMTP", select "Optional (TLS)".

If none of the above works:

  1. make sure "use submission port (587)" under Sending Mail is not ticked (and there is no colon and port number in SMTP server)
  2. scroll down even further and you should see "Ports & Protocols". There, next to SMTP port, please put "2525", click "OK"
  3. try to send again.

In short, if you can't send try 587, and if where you are is blocking that too, try 2525.

Diagnosis: confirming blocked ports

On occasion, problems with Eudora or some recently-installed antivirus software or firewall may cause similar problems.  To confirm that the problem is port blocking on the connection, you can start a terminal to run telnet.  On Windows, click Start > "Run...> and type "cmd" to get a Command Prompt box.  For a Mac, go to Finder > Applications > Utilities > Terminal.

To check whether port 25 is blocked, for instance, type:

  telnet 25

and press the Enter key.  It should connect and you should see "220 ESMTP Postfix [ NO UBE C=GB ] You are neither permitted nor authorised to send unsolicited bulk email..."

If you don't, or it just hangs there, then probably that port is blocked.  Try the same thing, but with 587 instead of 25.  Other possibilities are 2525 or 465 (which won't give the message if it connects).  If you get a completely different message it may be an antivirus proxy, either on your computer or on the network you are connected to.

If you are using Windows Vista or 7, you may get an error that there is no such command as "telnet".   You can enable the telnet client with Start > Control Panel > Programs And Features >Turn Windows features on or off > Tick "Telnet Client" > OK.