"Not a valid email address"

[flintforge]

Hi,
First many thanks for writing denomailer ! (This inner log:true option makes it very convenient to debug!)

Description of the bug

Writing emails to user@domain
with domain not being a FQDN with a TLD but a host
is a very convenient way to send signals to admins
and is usually the first try that I give to an SMTP lib.

So I'm sending emails to me@localhost : yes, that's a valid email address
("although ICANN highly discourages dotless email addresses[1]")

However the lib replies :
Error: No valid emails provided!
Which is a bit vague in regard to the address

Same goes for the sender address:
Error: The specified from adress is not a valid email adress.
a clearer message, however with two typos

A look at the validator email → email.ts:19
shows one regexp, which will eventually considers faulty ones as valid :

• john..doe@example.org (double dot)
• 1234567890123456789012345678901234567890123456789012345678901234+x@example.com > 64 bytes
• and a few others invalid match/mismatch, see : https://en.wikipedia.org/wiki/Email_address

Validating email address is a complex expression. May I recommend :

• using an external heavily tested library
• adding an option to bypass the validity check of email address and just let the MTA do the job,
  by sending mail delivery status and/or simply rejecting them ?