[Mailman-Users] mailman on google comput engine

Mark Sapiro mark at msapiro.net
Thu Mar 21 13:44:22 EDT 2019

On 3/20/19 11:40 PM, 황병희 wrote:
> i just did make one vm instance Ubuntu 18.04 on google compute
> engine. barely i did install postfix at there. hmm if possible, i wish
> to run mailing service for my family and me -- it needs a little bit some comunication plus some
> records about family history. yes i want GNU Mailman very
> much!!! google compute engine blocked port 25 by default. in this case i
> can run mailman with other port (example 625)? again question, Mailman
> can act with 625 or 1625 or 2625, ...?

Are you talking incoming or outgoing mail. There are multiple pieces
involved. If incoming port 25 is blocked, Postfix won't be able to
receive incoming mail to the list and you're dead at that point.

Presumably, it is only outgoing port 25 that is blocked. By default
Mailman delivers to the local MTA at localhost:25 which may or may not
be blocked but probably isn't. You can change these by setting SMTPHOST
and SMTPPORT in mm_cfg.py, but if you are going to deliver via the local
Postfix, Postfix will relay the outgoing mail to port 25 at the
recipient MXs. You can't really change that because you can't tell the
recipient MXs to listen on other ports.

You can get Postfix to relay via another MTA, e.g. at your ISP, and
authenticate to it.

If your Mailman is 2.1.23 or later (the Ubuntu 18.04 package is 2.1.26)
you can get Mailman to relay directly to an outside MTA with
authentication via the mm_cfg.py settings SMTP_AUTH, SMTP_USER,

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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