TACWeb Support Section:

You can receive email but can't send mail?

You probably need to change your outgoing SMTP server port number

If you have setup your email account in your email software, and you can receive mail but can't send mail, it's probably your ISP blocking port 25.

Internet Service Providers (ISP), like Verizon, Comcast, ATT, Sprint, etc. often block the SMTP port 25. This port is standard for sending email. But it's also used for sending spam, so ISPs today often block it.

In order to send email, you just have to change your outgoing SMTP server port number from 25 to either 2525 or 587.

Here's how to change the port number in some popular email software.


1. Tools > Account Settings.
2. Select your email account from the list. Click Change.
3. Click More Settings.
4. Check the "My outgoing server (SMTP) requires authentication" box.
5. Make sure that "Use same settings as my incoming mail server" is selected.
6. Click the Advanced tab.
7. Change the Outgoing Server field number from 25 to 587.
8. Click OK.
9. Click Next until you reach the Finish button. Click Finish.

Outlook Express

1. Tools > Accounts.
2. Click the Mail tab.
3. Select your email account from the list. Click the Properties button.
4. Make sure the "Include this account when receiving mail or synchronizing" box is checked.
5. Click the Servers tab. Locate the Settings button below Outgoing Mail Server. Click it.
6. Locate the SMTP Port field. Change the 25 to 587.
7. Make sure the "My SMTP server requires authentication" box is checked.
8. Click OK. Click OK again until you've closed all windows.
9. Restart Outlook Express.


1. Open Preferences in the Mail menu.
2. Click the Accounts tab to locate your account. Open it.
3. Open the Outgoing Mail Server window.
4. Change the number in the Port field from 25 to 587.
5. Check the "Use Authentication" box.
6. Click Continue.
7. Click Continue again. Close any remaining windows.


I 1. touch/open "Settings" icon.
2. touch/open "Mail, Contacts, Calendars".
3. on accounts, choose the account you wish to change the port for.
4. touch/open "account".
5. touch/open "SMTP" under "outgoing mail server".
6. touch/open your "primary server".
7. on the bottom, touch/open "server port"
8. change the port from "25" to "587".
9. touch/open "done".


I 1. Open Preferences.
2. Locate the SMTP Port field. Change 25 to 587.
3. Change "Use submission port (587)" to ON.
4. Change "Allow authentication" to ON.
5. Click OK. Close Preferences.

TAC • Buffalo, NY 14217 • 1-800-235-6865 • Tel (716) 874-5155 • Fax (716) 874-7283