On 8/18/2011 8:53 AM, Carlos Mennens wrote:
Today I received a ticket for altering the way my Postfix server
handles mail and I don't understand it. The ticket / request is pasted
below:
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According to RFC 4409 client mail submission to an email server is
supposed to use port 587.
Server to server SMTP relays are to use port 25.
When I am not at the office, I can't email via my work (Postfix)
account via my iphone or my residential internet because my ISP(s)
filter port 25 to only allow traffic to and from their mail servers.
They do however allow 587 anywhere per RFC 4409.
Additionally I can't email to the IDE with my gmail account, this is
becoming a real pain in the ass when I need to send emails with
attachments.
Just to send this email I am having to relay off my own server in California.
Can we please get the proper ports opened on the mail server?
http://www.ietf.org/rfc/rfc4409.txt
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Now my question is I just want to be sure I'm correct in assuming that
all mail servers send on port 25, correct? This user just is
requesting me to allow relay access from his phone carriers network or
home ISP which I'm not going to do since this is the reason I manage
webmail for users. Does the above request seem legit or strange? I
don't know enough about Postfix / mail& port 587 to know if this is a
legit request.
Thanks for any clarification!
Carlos,
This is a direct quote from a bot running in #postfix on freenode:
Port 587 is submission, for user submission of mail, NOT suitable for
mail exchange. See the commented example in master.cf. also
see !msa, and rfc 2476 and 4409. Also read
http://www.maawg.org/sites/maawg/files/news/MAAWG_Port25rec0511.pdf
Also have a look at:
http://www.postfix.org/SASL_README.html
-Matt
