Entourage, mail not sending, and port 25 vs 587

[jonpb]

Hi all,

Last night I noticed I could no longer send email through Entourage. I can receive, have net access, etc... but I can not send mail unless I change my outgoing mail to override port 25.

Apparently I've been blocked by my isp, they said I could have spyware attempting to send large amounts of email from my account. This doesn't add up, but I thought I'd put the question to you fine folks to see what info/help you could offer.

Comcast is the ISP. MBPro, 2.4ghz, 4G ram.

Can anyone shed a little light on this?

MANY thanks in advance.

[jonpb]

[EDIT]
SO I saw this:
http://arstechnica.com/news.ars/post/20040629-3945.html
Are there any trojans/viruses/malware to mac my mac a zombie? I don't know of any, but reading this makes me concerned. I'm behind a firewall, stealth mode, and access list, and am WPA2. Little snitch reports no unauthorized outbound connectionsm but still, a bit concerned.

Anyone?

[MisterMe]

Originally Posted by jonpb

...

Last night I noticed I could no longer send email through Entourage. I can receive, have net access, etc... but I can not send mail unless I change my outgoing mail to override port 25.

...

Can anyone shed a little light on this?

...

I have no idea what your issue is. As much as you may believe that it is an issue with Entourage, it is not. Port 25 and Port 587 are both SMTP (outgoing mail server) ports. Do you believe that your ISP should use only Port 25? ISPs commonly do not allow SMTP access to foreign servers on Port 25. This is a security measure which is designed to thwart spammers. Many, however, allow SMTP access to foreign servers on Port 587. Although you did not say so, I believe that you are sending email from a domain outside the one that hosts your email account. If this is the case, then you should be relieved.

[jonpb]

I didn't mean to imply that this is an Entourage issue, and I'm aware that many ISPs block port 25. I also don't feel they should *only* use port 25 -I just wanted to know why this happened all of a sudden. There was no advance notice, etc....

Your suspicion is correct: I do in fact send mail from smtp.mydomain.com (as opposed to smtp.comcast.net). This is likely the cause.

Thanks for the reply MisterMe.

[MisterMe]

Originally Posted by jonpb

... -I just wanted to know why this happened all of a sudden. ...

The explanation could not be simpler. The remote domain that you were going through has only recently begun to block Port 25 access.

[pjeski]

587 is generally called the "submission" port. It is SMTP with auth required. If you can send mail on port 587, then all is cool.