451 4.3.5 Server configuration error

When I rebuild postfix configuration via Postfix Mail Server Manager as follows:

[checked] ClamAV, Amavis & Spamassassin, Requires 1Gb+ RAM
[checked]  Drop all emails if no rDNS/PTR
[checked]    Installs DKIM & SPF, enables DKIM for New Accounts and Domains
[NOT checked] Installs DKIM & SPF, enables DKIM for New Accounts and Domains

I'm unable to send an email to the server from an outside domain. When I say outside, I mean it's hosted on another server.

Email bounces back with:

Out: 220 CENTOSWEBPANELBASED_SERVER_HERE ESMTP Postfix
 In:  EHLO EXTERNAL_SERVER_HERE
 Out: 250-CENTOSWEBPANELBASED_SERVER_HERE
 Out: 250-PIPELINING
 Out: 250-SIZE 204800000
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250-AUTH PLAIN LOGIN
 Out: 250-AUTH=PLAIN LOGIN
 Out: 250-ENHANCEDSTATUSCODES
 Out: 250-8BITMIME
 Out: 250 DSN
 In:  STARTTLS
 Out: 220 2.0.0 Ready to start TLS
 In:  EHLO EHLO EXTERNAL_SERVER_HERE
 Out: 250-CENTOSWEBPANELBASED_SERVER_HERE
 Out: 250-PIPELINING
 Out: 250-SIZE 204800000
 Out: 250-ETRN
 Out: 250-AUTH PLAIN LOGIN
 Out: 250-AUTH=PLAIN LOGIN
 Out: 250-ENHANCEDSTATUSCODES
 Out: 250-8BITMIME
 Out: 250 DSN
 In:  MAIL FROM:EXTERNAL_EMAIL_HERE SIZE=5109
 Out: 250 2.1.0 Ok
 In:  RCPT TO:CWPBASEDEMAIL HERE
 Out: 451 4.3.5 Server configuration error
 In:  DATA
 Out: 454 4.5.1 Error: no valid recipients
 In:  QUIT
 Out: 221 2.0.0 Bye

however if I uncheck ClamAV, Amavis & Spamassassin, Requires 1Gb+ RAM everything's is fine.  I checked mail log and found something that could relate to it:

postfix/smtp[3625]: certificate verification failed for EXTERNALSERVER_HERE

Any clues?

Hello,

Mail server only works fine once you have proper hostname and reverse record for the hostname IP. without this hotmail, yahoo, gmail reject your emails and marked spam as well they also won't sent email to the server email ID.

so first setup your proper hostname, add reverse PTR record for your hostname and then Rebuild the mail server again. make sure when you rebuild mail server your PTR record must resolve on proper Hostname. and once it done it should work like Professional mail server.

I already set hostname and reverdns properly. Everything was working fine for a month or so until I decided to rebuild configuration via postfix manager using clamd, spamd,... No matter what domain I send it from (even non yahoo,gmail, ones) email bounces back. However if I rebuild configuration without "clamd, spamd" checked everything seems fine.

I'm not sure if it's a bug or something else, but once I rebuild configuration without clamd,spamd, services still seem to be installed and active, however emails don't bounce anymore.

If email is sent within a server, everything works fine. I've even compared postfix/main.cf before and after rebuild and it's exactly the same.

you will need to check mail-server logs with your sysadmin or hosting support as this could be something specific.

I had the same error over the past week and had to rebuld with ClamAV, Amavis & Spamassassin, Requires 1Gb+ RAM unchecked

no big deal though as everything works perfectly once i manually start clamav and amavis

I had the same error over the past week and had to rebuld with ClamAV, Amavis & Spamassassin, Requires 1Gb+ RAM unchecked

no big deal though as everything works perfectly once i manually start clamav and amavis essay writing service

Hi! Is there a tutorial anywhere? Unfortunately, my skills aren't good enough to figure everything out on my own.