IMSVA changes some mail recipients unexpectedly, while there are no policy rules configured with the action “change recipient”.
IMSVA uses Postfix as Mail Transfer Agent (MTA) to relay mails. Postfix, by default, rewrites illegal mail addresses on headers for outgoing mails, if the sender IP is $mynetworks. As a result, when a mail’s recipient address in the “To:” header violates RFC 2822, Postfix will rewrite it. The result may not be expected though.
To disable address rewriting on Postfix, do the following:
- Use PuTTY or other software to SSH to IMSVA using root account.
- Run the following commands:
postconf -e local_header_rewrite_clients=