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jessesalazar 18th November 2011 00:34

Problem port 25
I've followed the tutorial perfect server ubuntu 11.04, and everything is working pretty good, But when I send a message or receive from my external account it doesn't work, because my ISP is blocking the port 25, so, I went to no-ip webpage and add an "alternate smtp" and "reflector", now I can receive message using the port 587, but when I setup the to use auth sasl, like no-ip said, sending message doesn't work. here is the setup for smtp:
Use the following settings:

Outgoing SMTP Server:
Port Number: 3325 or 587
Password: <Set on, see above.
Defaults to your No-IP account password>

smtp_sasl_auth_enable = yes
relayhost = [mail.isp.example]
# Alternative form:
# relayhost = [mail.isp.example]:submission
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd

# destination credentials
[mail.isp.example] username:password
# Alternative form:
# [mail.isp.example]:submission username:password

What else do I need to do?


eko_taas 1st December 2011 12:02

receiving port 25 easy workaround
I found easy solution for my receiving problem (blocked port 25) from

to shell (as su)

# iptables -t nat -A PREROUTING -p tcp --dport 587 -j REDIRECT --to-ports 25
Inspired by DydDNS discounts, I took 1y for EmailGateway

Zone Service Dyn Email Gateway to
Also I made MX settings on domain DNS

MX @
MX @
Now I should find out how to add that to ISPConfig firewall-script (that applies also on reboot...) - anyone with good advice, let me know (I found only quote old howtoforge-posts...)

eko_taas 7th December 2011 04:22

Firewall script
Could solve permanent issue based on mini-howto long time back:

Now I can receive and send my emails w/o ISP issues (seems that outgoing port not yet problem for them even if told so.....)

eko_taas 7th December 2011 15:10

now I needed smtp-relay as well
My ISP closed sending port after few trials, so now I added relay as well.

Got it running w/o pain based on

I am using one of my (new/extra) ISP-email-accounts just to login to ISP's smtp (as relay i.e normal ports OK).....

Now now both receiving and sending working like a charm for all server1-accounts :D

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