==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):  1.3.1
- Deployed with iRedMail Easy or the downloadable installer? easy
- Linux/BSD distribution name and version: ubuntu 18.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  mysql
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? standard
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hi Guys,

I'm getting the status=deferred when sending to yahoo and also not able to receive mail from yahoo.

Can somebody extend help.

Thank you so much.

Please find below the log from /var/log/maillog.

======================
"Nov  1 08:34:12 bit postfix/smtp[26722]: Trusted TLS connection established to mta6.am0.yahoodns.net[67.195.228.110]:25: TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)
Nov  1 08:34:12 bit postfix/smtp[26722]: 4HjMCk6XyJz2hLJx: host mta6.am0.yahoodns.net[67.195.228.110] said: 421 4.7.0 [TSS04] Messages from MyIPAddess temporarily deferred due to unexpected volume or user complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes (in reply to MAIL FROM command)
Nov  1 08:34:12 bit postfix/smtp[26722]: 4HjMCk6XyJz2hLJx: lost connection with mta6.am0.yahoodns.net[67.195.228.110] while sending RCPT TO
Nov  1 08:34:14 bit postfix/smtp[26722]: Trusted TLS connection established to mta7.am0.yahoodns.net[67.195.228.106]:25: TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)
Nov  1 08:34:14 bit postfix/smtp[26722]: 4HjMCk6XyJz2hLJx: to=<myemail@yahoo.com>, relay=mta7.am0.yahoodns.net[67.195.228.106]:25, delay=3.9, delays=0/0/3.6/0.23, dsn=4.7.0, status=deferred (host mta7.am0.yahoodns.net[67.195.228.106] said: 421 4.7.0 [TSS04] Messages from MyIPAddress temporarily deferred due to unexpected volume or user complaints - 4.16.55.1; see https://postmaster.yahooinc.com/error-codes (in reply to MAIL FROM command))"
===============

Note: DMARC,DKIM,SPF is working fine.