host mx1.kvnbw.de[194.0.94.38] said: 550 5.1.1: Recipient address rejected: undeliverable address: host smtpin1.kvnbw.net[10.240.116.11] said: 550 5.1.1 Recipient address rejected:
undeliverable address: Unknown Recipient Address Lookup (in reply to
RCPT
Die eingegebene Mail-Adresse ist korrekt - an was kann das liegen?