RCPT TO same address multiple times

[zypA13510]

This happens when TO and CC contain the same address. Emailjs will try to RCPT TO that same address multiple times. And for me (using Exchange 365 SMTP server) it throws a timed out error.

Rfc2822 does not seem to forbid an address to appear in TO and CC at the same time. Also, this is possible using mailx (hostname, IP and mail address redacted):

$ echo "Testing email with the same TO and CC recipient." | mailx -v -r '"no-reply" <[email protected]>" -s "Test email" -S smtp="mail.example.com:25" -c [email protected] [email protected]
Resolving host mail.example.com . . . done.
Connecting to 10.0.0.1:25 . . . connected.
220 mail.example.com Microsoft ESMTP MAIL Service ready at Mon, 7 Oct 2019 12:46:57 +0800
>>> HELO localhost
250 mail.example.com Hello [10.0.0.1]
>>> MAIL FROM:<[email protected]>
250 2.1.0 Sender OK
>>> RCPT TO:<[email protected]>
250 2.1.5 Recipient OK
>>> DATA
354 Start mail input; end with <CRLF>.<CRLF>
>>> .
250 2.6.0 <●●●●●●●●●●●●●●●●●●●●●●●●●●[email protected]> [InternalId=●●●●●●●●] Queued mail for delivery
>>> QUIT
221 2.0.0 Service closing transmission channel

The email received has Alice on both TO and CC.

To fix this, I think a dedupe step for RCPT only should be added before SMTP send.

[zackschuster]

fixed in 265b88a :)

[zackschuster]

@zypA13510 this is now live in 3.0.0.