so im configuring postfix as my email server as per the instructions here:

https://library.linode.com/email/postfix/postfix2.9.6-dovecot2.0.19-mysql

and so far i can receive emails fine, but i get a timeout error when trying to send email in thunderbird.

checking /var/log/mail.log :

Nov 13 17:39:43 neptune postfix/smtp[25513]: 5D153FFE1E: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=63469, delays=63468/0.04/0.74/0.15, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:42:43 neptune dovecot: imap-login: Disconnected (no auth attempts): rip=68.185.32.59, lip=173.255.215.95, TLS: Disconnected
Nov 13 17:42:52 neptune dovecot: imap-login: Disconnected (no auth attempts): rip=68.185.32.59, lip=173.255.215.95, TLS: Disconnected
Nov 13 17:44:05 neptune postfix/pickup[25291]: DE9EAFFE34: uid=33 from=<www-data>
Nov 13 17:44:05 neptune postfix/cleanup[25523]: DE9EAFFE34: message-id=<20131113174405.DE9EAFFE34@neptune.squattheplanet.com>
Nov 13 17:44:05 neptune postfix/qmgr[23619]: DE9EAFFE34: from=<www-data@neptune.squattheplanet.com>, size=8528, nrcpt=1 (queue active)
Nov 13 17:44:07 neptune postfix/smtp[25527]: DE9EAFFE34: to=<indiglosk8@gmail.com>, relay=gmail-smtp-in.l.google.com[2607:f8b0:400e:c01::1b]:25, delay=2, delays=0.06/0.01/0.26/1.7, dsn=2.0.0, status=sent (250 2.0.0 OK 1384364647 am2si4023933pad.38 - gsmtp)
Nov 13 17:44:07 neptune postfix/qmgr[23619]: DE9EAFFE34: removed
Nov 13 17:44:42 neptune postfix/qmgr[23619]: 6A9A9FFE33: from=<www-data@neptune.squattheplanet.com>, size=8230, nrcpt=1 (queue active)
Nov 13 17:44:43 neptune postfix/smtp[25527]: 6A9A9FFE33: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=409, delays=409/0/0.42/0.09, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:49:42 neptune postfix/qmgr[23619]: 06591FFE2D: from=<www-data@neptune.squattheplanet.com>, size=8587, nrcpt=1 (queue active)
Nov 13 17:49:43 neptune postfix/smtp[25799]: 06591FFE2D: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=55143, delays=55142/0.61/0.39/0.1, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:53:18 neptune postfix/pickup[25291]: BF9D8FFE34: uid=33 from=<www-data>
Nov 13 17:53:18 neptune postfix/cleanup[25816]: BF9D8FFE34: message-id=<20131113175318.BF9D8FFE34@neptune.squattheplanet.com>
Nov 13 17:53:18 neptune postfix/qmgr[23619]: BF9D8FFE34: from=<www-data@neptune.squattheplanet.com>, size=8260, nrcpt=1 (queue active)
Nov 13 17:53:19 neptune postfix/smtp[25820]: BF9D8FFE34: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=0.84, delays=0.07/0.01/0.21/0.55, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:54:42 neptune postfix/qmgr[23619]: 6A9A9FFE33: from=<www-data@neptune.squattheplanet.com>, size=8230, nrcpt=1 (queue active)
Nov 13 17:54:43 neptune postfix/qmgr[23619]: DAB83FFE1B: from=<www-data@neptune.squattheplanet.com>, size=8220, nrcpt=1 (queue active)
Nov 13 17:54:43 neptune postfix/smtp[25820]: 6A9A9FFE33: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=1009, delays=1008/0.52/0.12/0.04, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:54:43 neptune postfix/smtp[25820]: DAB83FFE1B: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=64589, delays=64588/0.27/0.46/0.03, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 17:58:04 neptune postfix/scache[25824]: statistics: start interval Nov 13 17:54:43
Nov 13 17:58:04 neptune postfix/scache[25824]: statistics: domain lookup hits=0 miss=1 success=0%
Nov 13 17:58:04 neptune postfix/scache[25824]: statistics: address lookup hits=0 miss=1 success=0%
Nov 13 17:58:04 neptune postfix/scache[25824]: statistics: max simultaneous domains=1 addresses=1 connection=1
Nov 13 17:59:42 neptune postfix/qmgr[23619]: BF9D8FFE34: from=<www-data@neptune.squattheplanet.com>, size=8260, nrcpt=1 (queue active)
Nov 13 17:59:42 neptune postfix/smtp[25831]: BF9D8FFE34: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=384, delays=384/0.22/0.09/0.16, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:01:31 neptune postfix/smtpd[25833]: connect from mail-wg0-f54.google.com[74.125.82.54]
Nov 13 18:01:37 neptune postfix/smtpd[25833]: NOQUEUE: reject: RCPT from mail-wg0-f54.google.com[74.125.82.54]: 550 5.1.1 <matt@squattheplanet.com>: Recipient address rejected: User unknown in virtual mailbox table; from=<omensandportents+caf_=matt=squattheplanet.com@gmail.com> to=<matt@squattheplanet.com> proto=ESMTP helo=<mail-wg0-f54.google.com>
Nov 13 18:01:37 neptune postfix/smtpd[25833]: disconnect from mail-wg0-f54.google.com[74.125.82.54]
Nov 13 18:04:42 neptune postfix/qmgr[23619]: 1AC5CFFE30: from=<www-data@neptune.squattheplanet.com>, size=8829, nrcpt=1 (queue active)
Nov 13 18:04:44 neptune postfix/smtp[25843]: 1AC5CFFE30: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=8776, delays=8775/0.87/0.58/0.16, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:04:57 neptune postfix/anvil[25835]: statistics: max connection rate 1/60s for (smtp:74.125.82.54) at Nov 13 18:01:31
Nov 13 18:04:57 neptune postfix/anvil[25835]: statistics: max connection count 1 for (smtp:74.125.82.54) at Nov 13 18:01:31
Nov 13 18:04:57 neptune postfix/anvil[25835]: statistics: max cache size 1 at Nov 13 18:01:31
Nov 13 18:05:30 neptune postfix/smtpd[25848]: connect from 68-185-32-59.static.knwc.wa.charter.com[68.185.32.59]
Nov 13 18:06:49 neptune postfix/smtpd[25848]: lost connection after UNKNOWN from 68-185-32-59.static.knwc.wa.charter.com[68.185.32.59]
Nov 13 18:06:49 neptune postfix/smtpd[25848]: disconnect from 68-185-32-59.static.knwc.wa.charter.com[68.185.32.59]
Nov 13 18:09:42 neptune postfix/qmgr[23619]: A6EBFFFE31: from=<www-data@neptune.squattheplanet.com>, size=10099, nrcpt=1 (queue active)
Nov 13 18:09:42 neptune postfix/qmgr[23619]: BF9D8FFE34: from=<www-data@neptune.squattheplanet.com>, size=8260, nrcpt=1 (queue active)
Nov 13 18:09:42 neptune postfix/qmgr[23619]: 6CF53FFE32: from=<www-data@neptune.squattheplanet.com>, size=7891, nrcpt=1 (queue active)
Nov 13 18:09:42 neptune postfix/smtp[26133]: BF9D8FFE34: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=984, delays=984/0.07/0.08/0.07, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:09:42 neptune postfix/smtp[26134]: 6CF53FFE32: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=4631, delays=4630/0.06/0.07/0.07, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:09:43 neptune postfix/smtp[26132]: A6EBFFFE31: host mx6.hushmail.com[65.39.178.135] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command)
Nov 13 18:09:43 neptune postfix/smtp[26132]: A6EBFFFE31: to=<fourier.c@hushmail.com>, relay=mx8.hushmail.com[65.39.178.142]:25, delay=8770, delays=8769/0.18/1.1/0.09, dsn=4.1.8, status=deferred (host mx8.hushmail.com[65.39.178.142] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command))
Nov 13 18:10:09 neptune postfix/anvil[25850]: statistics: max connection rate 1/60s for (smtp:68.185.32.59) at Nov 13 18:05:30
Nov 13 18:10:09 neptune postfix/anvil[25850]: statistics: max connection count 1 for (smtp:68.185.32.59) at Nov 13 18:05:30
Nov 13 18:10:09 neptune postfix/anvil[25850]: statistics: max cache size 1 at Nov 13 18:05:30
Nov 13 18:13:31 neptune postfix/smtpd[26138]: connect from mail-wi0-f176.google.com[209.85.212.176]
Nov 13 18:13:32 neptune postfix/smtpd[26138]: NOQUEUE: reject: RCPT from mail-wi0-f176.google.com[209.85.212.176]: 550 5.1.1 <matt@squattheplanet.com>: Recipient address rejected: User unknown in virtual mailbox table; from=<omensandportents+caf_=matt=squattheplanet.com@gmail.com> to=<matt@squattheplanet.com> proto=ESMTP helo=<mail-wi0-f176.google.com>
Nov 13 18:13:32 neptune postfix/smtpd[26138]: disconnect from mail-wi0-f176.google.com[209.85.212.176]
Nov 13 18:14:42 neptune postfix/qmgr[23619]: 6A9A9FFE33: from=<www-data@neptune.squattheplanet.com>, size=8230, nrcpt=1 (queue active)
Nov 13 18:14:42 neptune postfix/smtp[26146]: 6A9A9FFE33: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=2208, delays=2208/0.09/0.17/0.2, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:16:52 neptune postfix/anvil[26140]: statistics: max connection rate 1/60s for (smtp:209.85.212.176) at Nov 13 18:13:31
Nov 13 18:16:52 neptune postfix/anvil[26140]: statistics: max connection count 1 for (smtp:209.85.212.176) at Nov 13 18:13:31
Nov 13 18:16:52 neptune postfix/anvil[26140]: statistics: max cache size 1 at Nov 13 18:13:31
Nov 13 18:19:42 neptune postfix/qmgr[23619]: 82DCFFFE2F: from=<www-data@neptune.squattheplanet.com>, size=8814, nrcpt=1 (queue active)
Nov 13 18:19:43 neptune postfix/smtp[26164]: 82DCFFFE2F: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=25534, delays=25533/0.25/0.59/0.12, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:24:36 neptune postfix/pickup[25828]: D52F8FFE35: uid=33 from=<www-data>
Nov 13 18:24:36 neptune postfix/cleanup[26176]: D52F8FFE35: message-id=<20131113182435.D52F8FFE35@neptune.squattheplanet.com>
Nov 13 18:24:36 neptune postfix/qmgr[23619]: D52F8FFE35: from=<www-data@neptune.squattheplanet.com>, size=8065, nrcpt=1 (queue active)
Nov 13 18:24:39 neptune postfix/smtp[26180]: D52F8FFE35: host mx1.hushmail.com[65.39.178.200] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command)
Nov 13 18:24:40 neptune postfix/smtp[26180]: D52F8FFE35: to=<fourier.c@hushmail.com>, relay=mx6.hushmail.com[65.39.178.135]:25, delay=6, delays=2.8/2/1.2/0.03, dsn=4.1.8, status=deferred (host mx6.hushmail.com[65.39.178.135] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command))
Nov 13 18:24:42 neptune postfix/qmgr[23619]: 4A12AFFE2A: from=<www-data@neptune.squattheplanet.com>, size=7953, nrcpt=1 (queue active)
Nov 13 18:24:42 neptune postfix/qmgr[23619]: 02533FFE2B: from=<www-data@neptune.squattheplanet.com>, size=10132, nrcpt=1 (queue active)
Nov 13 18:24:42 neptune postfix/pickup[25828]: 75196FFE36: uid=33 from=<www-data>
Nov 13 18:24:42 neptune postfix/cleanup[26176]: 75196FFE36: message-id=<20131113182442.75196FFE36@neptune.squattheplanet.com>
Nov 13 18:24:42 neptune postfix/qmgr[23619]: 75196FFE36: from=<www-data@neptune.squattheplanet.com>, size=7972, nrcpt=1 (queue active)
Nov 13 18:24:42 neptune postfix/smtp[26186]: 75196FFE36: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=0.19, delays=0.01/0.01/0.11/0.06, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:24:42 neptune postfix/smtp[26182]: 02533FFE2B: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=42365, delays=42364/0.03/0.22/0.06, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:24:42 neptune postfix/smtp[26180]: 4A12AFFE2A: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=42528, delays=42528/0.08/0.27/0.07, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:29:42 neptune postfix/qmgr[23619]: BF9D8FFE34: from=<www-data@neptune.squattheplanet.com>, size=8260, nrcpt=1 (queue active)
Nov 13 18:29:43 neptune postfix/qmgr[23619]: 75196FFE36: from=<www-data@neptune.squattheplanet.com>, size=7972, nrcpt=1 (queue active)
Nov 13 18:29:43 neptune postfix/qmgr[23619]: D52F8FFE35: from=<www-data@neptune.squattheplanet.com>, size=8065, nrcpt=1 (queue active)
Nov 13 18:29:43 neptune postfix/smtp[26195]: D52F8FFE35: host mx3.hushmail.com[65.39.178.142] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command)
Nov 13 18:29:44 neptune postfix/smtp[26195]: D52F8FFE35: to=<fourier.c@hushmail.com>, relay=mx4.hushmail.com[65.39.178.143]:25, delay=310, delays=309/0.08/0.92/0.11, dsn=4.1.8, status=deferred (host mx4.hushmail.com[65.39.178.143] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to MAIL FROM command))
Nov 13 18:29:45 neptune postfix/smtp[26193]: BF9D8FFE34: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=2187, delays=2184/0.27/2.2/0.07, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))
Nov 13 18:29:45 neptune postfix/smtp[26194]: 75196FFE36: to=<omensandportents@riseup.net>, relay=mx1.riseup.net[198.252.153.129]:25, delay=303, delays=301/0.08/2.2/0.07, dsn=4.1.8, status=deferred (host mx1.riseup.net[198.252.153.129] said: 450 4.1.8 <www-data@neptune.squattheplanet.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))

so, judging by the last few entries, either i don't have my mx/dns records set up correctly, or my mail server is incorrectly configured to allow mail outside of it's domain? im not really sure...

here's my dns settings:



im not sure if i have this set right, can someone help me out?

Your system hostname claims to be "neptune.squattheplanet.com", which does not appear in the DNS. Add A/AAAA record(s) for that and other mail servers will be more likely to accept mail from you.

_________________

/* TODO: need to add signature to posts */

ok, i put that in the A/AAAA record and all the sudden im starting to get emails from my forums again! yay!

i'm still getting a timeout error in thunderbird when trying to send mail, so i'm guessing the problem now is related to my imap settings on the server?

Usually, that means your ISP is blocking connections to port 25. If you can't connect to mail.hoopycat.com port 25, that is the case.

Port 587 (submission) is used for this purpose... uncomment the "submission" section in master.cf and postfix will start listening to port 587 on its next restart. (Remember to use "permit_sasl_authenticated,reject" or something similar for smtpd client restrictions.)

_________________

/* TODO: need to add signature to posts */

i don't think that's the issue, i tried your suggestion and uncommented both the submission section of master.cf and the permit_sasl_authenticated,reject section and i'm still getting the same error.