Meta's emails and Pipelining not supported with smtpd

Hi.

I've noticed that verification code from WhatsApp send via email is not
arriving to my SMTP server which runs OpenSMTPd on OpenBSD 7.7/amd64.

This is what I see in /var/log/maillog:

> smtp connected address=69.171.232.141 host=69-171-232-141.mail-mail.facebook.com
> smtp tls ciphers=TLSv1.3:TLS_CHACHA20_POLY1305_SHA256:256
> smtp bad-input result="500 5.5.1 Invalid command: Pipelining not supported"
> smtp disconnected reason=quit

Did any of you notice this?

OpenBSD 7.7 (GENERIC.MP) #0: Sun May 4 11:23:50 MDT 2025
root@syspatch-77-amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP

--
Regards,
Mikolaj