Building a Functional Email Server

As one who actually configured the largest set of SMTP servers, I can attest to the power of Jane Street OCaml e-mail library and its extensible but safe way to deploy wide variety of mail servers without breakage.

Sendmail uses M4 macro; Postfix , INI; exim, INI; OpenSMTPd, INI.

Deployment always a mess and highly error-prone especially if you’re going out and doing it for other organizations or satellite offices.

If only the configuration variable name were actual nesting of code procedures/functions followed by a nice description, other admins wouldn’t be messing with what we don’t understand.

Perhaps like ‘SMTP.server.mail.header.reject_extra_ending_CR=1’

Or ‘LMTP.forwarder.filter.post.icap.header.add.extra=‘X-ICAP-milter-version=4’