[Dovecot] status=undeliverable (lost connection with mail.larptreff.de[private/dovecot-lmtp] while sending MAIL FROM)

[Thomas Leuxner]

Is there more detail needed to finally solve this? The temporary fails caused by LMTP not reaching the 'RCPT TO' stage get pretty annoying in the light of backscatter hitting the server:

Nov 19 08:16:09 spectre postfix/smtpd[21386]: NOQUEUE: reject: RCPT from emea01-am1-ndr.ptr.protection.outlook.com[157.56.116.99]: 450 4.1.1 <DC21DEC5-D7F9-41FE-B16C-1ECC8536C40F at leuxner.net>: Recipient address rejected: unverified address: lost connection with spectre.leuxner.net[private/dovecot-lmtp] while sending MAIL FROM; from=<cocacola0004 at mentesbrim.onmicrosoft.com> to=<DC21DEC5-D7F9-41FE-B16C-1ECC8536C40F at leuxner.net> proto=ESMTP helo=<emea01-am1-obe.outbound.protection.outlook.com>

To reproduce simply add 'reject_unverified_recipient' to 'smtpd_recipient_restrictions'...
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