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Change the SMTP port on Panther Server OS X Server
The mail server admin panels in Panther Server have changed from their equivalents in Jaguar Server, hiding the options to modify the port on which Postfix listens for SMTP connections. Combined with the trend of more ISPs blocking traffic on port 25, this has become a more popular problem.

The solution:
As root, edit the file /private/etc/postfix/, so it looks something like the following. I use port 2525 in this example; you can substitute it with any port you'd like to use...
# =====================================================================
# service type  private unpriv  chroot  wakeup  maxproc command + args
#               (yes)   (yes)   (yes)   (never) (100)
# =====================================================================
smtp      inet  n       -       n       -       -       smtpd
2525      inet  n       -       n       -       -       smtpd
  • This editing should consist of adding the last line given here.
  • Restart your mail service in 'Server Admin,' or restart your server, and you should be golden.
  • You will have to edit the mail clients' SMTP preferences to use this port. If your client is, this is simple and in the 'Accounts' pane of 'Preferences.'
  • Currently 2.22 / 5
  You rated: 4 / 5 (9 votes cast)

Change the SMTP port on Panther Server | 7 comments | Create New Account
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Change the SMTP port on Panther Server
Authored by: eagle on Dec 30, '04 11:16:14AM

Since SMTP is a standard service defined as using port 25, what is the benefit of doing this? It's not like any other server, trying to send mail to you, will know to connect on port 2525. What am I missing here?

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Change the SMTP port on Panther Server
Authored by: Gfx on Dec 30, '04 05:31:08PM

Using a mail reflector service like the one provides makes you able to run your own mail server (on a static or dynamic IP) even if your ISP block incoming mail on port 25. This is how I use it for the last 2 years without any problems so far.

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Port 587 (submission) is better
Authored by: dfe on Dec 30, '04 01:00:07PM

Instead of using the non-standard port 2525 for this I recommend using the standard mail submission port which is 587. This port is specifically for the case when you need to accept inbound mail from authenticated users. The port is already listed in /etc/services with the name submission.

A typical setup for a server processing both inbound and outbound mail would be to have a normal MTA (Mail Transfer Agent) set up on port 25 that accepts mail destined for local users (or accepts all mail based on IP or based on authentication) and then have a separate MSA (Mail Submission Agent) set up on port 587 which only accepts mail from authenticated users. With newer sendmail you can even avoid running any sort of milter-based spam filtering on mail coming in from the MSA port which both speeds up processing and avoids inadvertantly tagging outbound mail as spam for example in cases where someone connects through a dial-up account listed on several blacklists..

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Port 587 (submission) is better
Authored by: peertimo on Dec 31, '04 05:58:03AM

This does not solve the problem of the ISP blocking port 25 for SMTP. All this solves is having my server answer mail calls on port 2525 or 587. Once my mail server, Postfix, receives the mail, it has to send it out. This still goes through port 25, and as such is blocked by my ISP. What I need to configure is the way Postfix sends the mail out, so that I can fool the ISP and use another port, which is open, to actually send the mail out. The reason I want to do this is the size limitation of my ISPĀ“s outgoing mail server, 10 MB. Postfix will handle larger mails.

Any suggestions?

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Mount .DMG images remotely via the Terminal
Authored by: david-bo on May 23, '05 06:23:37PM

In earlier versions of Mac OS X (10.2?) you could simply

% open disk://host.tld/image.dmg

but doesn't work anymore, Any ideas why?


[ Reply to This | # ]
Change the SMTP-port
Authored by: david-bo on May 25, '05 02:32:26PM

Sorry for this. Stupd autofill function in Mozilla:-(

Anyway, what you asked for can't be done. It would require that you could change the configuration of the receiving SMTP-server.


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Port 587 (submission) is better
Authored by: graffixjones on Apr 11, '06 01:23:35PM

Well, I know this is a waaaay old thread, but I thought I'd offer my $.02.

My ISP (sbc yahoo) offers an 'opt out' method for the port 25 filter, so if anybody is using SBC Yahoo DSL and wishes to have the port 25 filter removed (to be able to use their own network mail server) just go to the link below, and use the 'Port 25 opt out' option in the pop-up.

Hope that helps somebody... as you can see I'm currently in the same situation, and I just filled out the form and hopefully the filter will be lifted within a day or two.

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