64 character limit on local part (before the @)

[embillo]

I am struggling to accept mail from a government agency whose sending email address is in both official languages and therefore very long: 74characterslong7890123456789012345678901234567890123456789012345678901234@xyz.com

Our ESA C100V is dropping these and even whitelisting the domain doesn't help as packet captures just show the conversation being dropped every time.  If I try a test with any 'from address' 64 characters or less@xyz.com - it works fine.

I am wondering if anybody knows if there is a setting or switch I can toggle to say "ignore" the default 64 character limit?

[Libin Varghese]

The format of email addresses is local-part@domain where the local part may be up to 64 characters long and the domain may have a maximum of 255 characters. The formal definitions are in RFC 5322 (sections 3.2.3 and 3.4.1) and RFC 5321.

I do not see an option to have ESA go against RFC.

Regards,

Libin Varghese