Eastlink + Port 25 SMTP

Has anyone with Eastlink broadband service ever figured out how to get them to turn off the filter they have in place on outbound Port 25 (SMTP) traffic? There was no filter in place on our ISN-branded Eastlink-provided broadband, so it must be possible.


Mark's picture
Mark on March 7, 2008 - 15:51 Permalink

I argued with them over this for a long time… They started blocking it after one of those mass email worms were circulating. They said it was only going to be temporary, but that was about 3 years ago. I moved and when I got hooked back up again, it started working again for me. After a week or so, it stopped again. The only way I found around it is to get their business service.

Chuck McKinnon's picture
Chuck McKinnon on March 7, 2008 - 19:38 Permalink

Do they support SMTP over SSL? That’s usually port 465; you might try that.

gm's picture
gm on March 7, 2008 - 22:24 Permalink

A lot of mail services (.mac for one) are providing smtp on alternate ports as well as ssl on prt 465. Take a look in their FAQ. I guess they realized that most ISP now block 25.

Peter Rukavina's picture
Peter Rukavina on March 11, 2008 - 03:01 Permalink

Somewhat cryptically, Eastlink Technical Support replied to my query on this with:

Thank you for your email. We are not blocking port 25. However, we do not allow residential customers to run their own email servers. If you must run a email server, I would suggest a business account.

Clearly they are blocking port 25. And I don’t actually want to “run my own email server” — I want to connect to my corporate email server.

In any case, the solution turned out to be simple. On our corporate mail server we opened up access on Port 587 for SMTP, which is an easy-to-configure option with Sendmail for RHEL, involving a simple change in /etc/sendmail.mc, uncommmenting:

DAEMON_OPTIONS(`Port=submission, Name=MSA, M=Ea’)

In Mail.app, I simply change the port for outgoing mail to 587. And I’m in business.

Steven Garrity's picture
Steven Garrity on March 11, 2008 - 03:07 Permalink

This change will help out when on hotel networks or other public networks that block port 25.

Peter Rukavina's picture
Peter Rukavina on March 11, 2008 - 13:04 Permalink

Note that I found that I also had to add the following line to also allow regular port 25 incoming email:

DAEMON_OPTIONS(`Port=smtp, Name=MTA’)dnl