Author: W B Hacker Date: To: exim users Subject: Re: [exim] Changing SMTP ports and Sender/Receiver verify stops
working!
exim wrote: > Today I added port 26 to my exim server using the daemon_smtp_ports option
> in the configuration file. I did this because some traveling salesmen can
> not send email on port 25 from their laptops to my server (yes it was a COX
> issue).
They should not even be trying to do so, as it makes your job harder w/r
filtering against garbage arrivals, and theirs harder w/r getting a connection -
travelign or fixed-base.
See below.
>
> Now all attempts fail, and it appears to happen during the sender and
> receiver verification. When a smtp session comes in using port 26, is exim
> performing all of it's verification calls using port 26 also?
No, none of them. Exim (MTA's in general) will use a 'random' port above 1024,
and usually *way* above that for an 'outbound' conneciton TO port 25 at the
distant end.
> If it is, is
> there a way around this? I don't want to turn off my receipient and sender
> verifications.
>
> Thank You,
>
> Terry Shows
> USA
>
>
The port you should be adding for that sort of submission is 587, and with TLS.
- it is provided for in RFC's
- MUA's expect it, are easily configured for it
- Lot's of folks can help with advice if the docs are too much work to read.
- Few 'connectivity' ISP's block it, as it is a 'known need' (26 is not such).
- So long as you require auth (with TLS) on 587, you need not do a lot of other
verification. If the arrival is not 'one of your own' they will not have a
valid UID:PWD. Or so you should insure...
