Why can I receive email but not send any?
There are two reasons this may be happening.
1. Authentication Failed You do need to authenticate before you can relay mail. This means you will need to use either SMTP Authentication (if your mail client supports it) or POP before SMTP (where you simply check your mail before sending).
You may also try checking your email prior to sending out email. If you are not using SMTP-Auth you must have checked your email within the 15 minutes prior to sending email so that the server can authenticate you as a valid user.
2. ISP is Blocking Port 25 If your ISP is blocking port 25 this will prevent you from using the standard SMTP port to send. Some ISPs do this so that you are forced to use their email servers when sending email, as an attempt to prevent spam. Some ISPs that have been known to block port 25 are Comcast, Earthlink, and AT&T. A quick test and possible workaround is to try changing the SMTP port setting in your email software to use port 1025 or 587, then try to send again.
Testing the Port 25 Connection
1.) If you have a Microsoft Windows machine, then click on Start -> Run
2.) Type in there cmd or command, if cmd doesn't work, and hit enter.
3.) A black window, in form of a small box will open up, in there type:
telnet yourdomainname 25 and hit enter
(make sure yourdomainname is in form of domainname.com, for example if your domain
name is ezpublishing, then you would type telnet ezpublishing.com 25)
4.) Once you hit enter, the screen should clear and it should show on the top:
220 someserver.com ESMTP and a blinking cursor on the bottom of that.
If this shows up as described, then your smtp is working. If not proceed to step 5.
5.) If you don't the message described in step 4, but instead you get an error, then the
problem is on your ISP's side. Please contact them and ask them why they're
blocking outgoing port 25 to other servers.
| Was this answer useful to you?