Alternate SMTP Port for Sending Outbound E-mail

Some ISPs, hotels and public Internet access networks block SMTP port 25 which is used to send your E-mail. Instead they force you to use their mail servers to send your outbound mail. The problem with This is that these mail servers are often black listed for sending out too much SPAM

It is also common for some public access networks to intercept your outgoing E-mail and redirect it to their mail servers. Again, the problem with this is that these mail servers are often black listed for sending out too much SPAM.

We know this is annoying and have come up with a solution which works 90% of the time. We have configured our E-mail server to listen on a second, non standard, TCP port that these networks usually do not block. Simply alter you account information, within your E-mail client software, to use port 2525 instead of the default port 25. You can also enable your email to be sent using SSL encryption over TCP port 587.  Here are some procedures on how to change the port using Microsoft Outlook, Outlook Express and OS X Mail.

To test if you can access port 2525 (or even 587) from the public network, try this:

  • Open a command prompt window
  • Using Windows press "Start", "Run...", type "cmd" in the Open box and
     press "Enter"
  • Using OS X open your "Applications" folder, "Utilities" and then
     "Terminal"
  • At the command prompt, type "telnet mail.atlantisnet.com 2525" or "telnet mail.atlantisnet.com 587" and press
     "Enter"
  • If the port you entered is not being blocked, you should get a response which reads
     "220 mail.atlantisnet.com". At this
     point simply type "QUIT" and press "Enter"
  • If port 2525 or 587 is bring blocked, you will get a "Connect failed" message

If you are able to connect to port 2525 or 587 then you can make the following changes:

Microsoft Outlook 2003:

  • Click on the "Tools" drop down menu
  • Select "E-mail Accounts..."
  • Select "View or change existing e-mail accounts" and press "Next >"
  • Select the E-mail account you want to modify and press "Change..."
  • Press "More Settings..."
  • Click the "Advanced" tab
  • Under the "Server Port Numbers" section, change the "Outgoing server
     (SMTP)" value from "25" to "2525" or "587"
  • Press "OK"
  • Press "Next >"
  • Press "Finish"

Microsoft Outlook 2007:

  • Click on the "Tools" drop down menu
  • Select "Account Settings..."
  • Click on the "E-mail" tab
  • Select the account hosted by AtlantisNet
  • Click on the "Change..." button
  • Click on the "More Settings..." button
  • Click the "Advanced" tab
  • Under the "Server Port Numbers" section, change the "Outgoing server
     (SMTP)" value from "25" to "2525" or "587"
  • Press "OK"
  • Press "Next >"
  • Press "Finish"

Microsoft Outlook Express:

  • Click on the "Tools" drop down menu
  • Select "Accounts..."
  • Click the "Mail" tab
  • Select the E-mail account you want to modify and press "Properties"
  • Click the "Advanced" tab
  • Under the "Server Port Numbers" section, change the "Outgoing mail (SMTP)" value from "25" to "2525" or "587"
  • Press "OK"
  • Press "Close"

OS X Mail:

  • Click on the "Mail" drop down menu
  • Click the "Accounts" icon
  • Select the E-mail account you want to modify
  • Click the "Account Information" tab
  • Press "Server Settings..."
  • Change the "Server Port:" from "25" to "2525" or "587"
  • Press "OK"
  • Close the "Accounts" window

If you are still unable to send your outbound mail, then here are some additional solutions:

  • Use our WebMail system at http://mail.atlantisnet.com
  • Use the SMTP server of the public access network you are using. A list of some ISPs mail servers can be found here

Here is an article which also explains the situation:
http://ask-leo.com/why_cant_i_send_mail_from_my_hotel_room.html