On 24.03.2018 11:32, Sven Wagner wrote:
On 23.03.2018 12:02, Marco Dickert wrote:

Zeige mal den Inhalt der Datei
/etc/postfix/header_checks. Zeige außerdem mal die Mail-Log-Einträge, wenn du
eine Mail vom System selbst schickst (also wenn der Fehler auftritt).
Hier der Auszug aus Mail-Log:

Mar 24 11:15:46 mail postfix/submission/smtpd[11182]: connect from dslb-088-067-160-015.088.067.pools.vodafone-ip.de[88.67.160.15]
Mar 24 11:15:47 mail postfix/submission/smtpd[11182]: 5FC3B607A4: client=dslb-088-067-160-015.088.067.pools.vodafone-ip.de[88.67.160.15], sasl_method=PLAIN, sasl_username=sven@domain.tld
Mar 24 11:15:47 mail postfix/cleanup[11185]: 5FC3B607A4: message-id=<5b45c863-7a32-87ea-9af0-986662367521@domain.tld>
Mar 24 11:15:47 mail postfix/qmgr[6582]: 5FC3B607A4: from=<sven@domain.tld>, size=552, nrcpt=6 (queue active)
Mar 24 11:15:47 mail dovecot: lmtp(11188): Connect from local
Mar 24 11:15:47 mail dovecot: lmtp(sven@domain.tld): CIypIFMltlq0KwAAqa3BHQ: sieve: msgid=<5b45c863-7a32-87ea-9af0-986662367521@domain.tld>: stored mail into mailbox 'INBOX'
Mar 24 11:15:47 mail postfix/lmtp[11187]: 5FC3B607A4: to=<sven@domain.tld>, orig_to=<bastelwastel@domain2.tld>, relay=mail.domain.tld[private/dovecot-lmtp], delay=0.22, delays=0.19/0.01/0.01/0.02, dsn=2.0.0, status=sent (250 2.0.0 <sven@domain.tld> CIypIFMltlq0KwAAqa3BHQ Saved)
Mar 24 11:15:47 mail dovecot: lmtp(andrea@domain3.tld): CIypIFMltlq0KwAAqa3BHQ:2: sieve: msgid=<5b45c863-7a32-87ea-9af0-986662367521@domain.tld>: stored mail into mailbox 'INBOX'
Mar 24 11:15:47 mail postfix/lmtp[11187]: 5FC3B607A4: to=<andrea@domain3.tld>, orig_to=<bastelwastel@domain2.tld>, relay=mail.domain.tld[private/dovecot-lmtp], delay=0.23, delays=0.19/0.01/0.01/0.02, dsn=2.0.0, status=sent (250 2.0.0 <andrea@domain3.tld> CIypIFMltlq0KwAAqa3BHQ:2 Saved)
Mar 24 11:15:47 mail dovecot: lmtp(11188): Disconnect from local: Successful quit
Mar 24 11:15:47 mail postfix/submission/smtpd[11182]: disconnect from dslb-088-067-160-015.088.067.pools.vodafone-ip.de[88.67.160.15] ehlo=2 starttls=1 auth=1 mail=1 rcpt=1 data=1 quit=1 commands=8
Mar 24 11:15:47 mail dovecot: imap(sven@domain.tld): Connection closed in=1017 out=38899
Mar 24 11:15:48 mail postfix/smtp[11189]: 5FC3B607A4: to=<mr@xxxxxx.xxx>, orig_to=<bastelwastel@domain2.tld>, relay=xxxxxxxx:25, delay=0.84, delays=0.19/0.04/0.26/0.36, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 8DA4116C0AF)
Mar 24 11:15:48 mail postfix/smtp[11186]: 5FC3B607A4: to=<xxxxx@gmail.com>, orig_to=<bastelwastel@domain2.tld>, relay=gmail-smtp-in.l.google.com[2a00:1450:400c:c06::1a]:25, delay=1.4, delays=0.19/0.02/0.68/0.49, dsn=2.0.0, status=sent (250 2.0.0 OK 1521886553 u69si8352098wrc.186 - gsmtp)
Mar 24 11:15:48 mail postfix/smtp[11186]: 5FC3B607A4: to=<yyyyyyy@gmail.com>, orig_to=<bastelwastel@domain2.tld>, relay=gmail-smtp-in.l.google.com[2a00:1450:400c:c06::1a]:25, delay=1.4, delays=0.19/0.02/0.68/0.49, dsn=2.0.0, status=sent (250 2.0.0 OK 1521886553 u69si8352098wrc.186 - gsmtp)
Mar 24 11:15:48 mail postfix/smtp[11186]: 5FC3B607A4: to=<zzzzzz@gmail.com>, orig_to=<bastelwastel@domain2.tld>, relay=gmail-smtp-in.l.google.com[2a00:1450:400c:c06::1a]:25, delay=1.4, delays=0.19/0.02/0.68/0.49, dsn=2.0.0, status=sent (250 2.0.0 OK 1521886553 u69si8352098wrc.186 - gsmtp)
Mar 24 11:15:48 mail postfix/qmgr[6582]: 5FC3B607A4: removed
Mar 24 11:15:55 mail dovecot: imap-login: Login: user=<sven@domain.tld>, method=PLAIN, rip=88.67.160.15, lip=93.90.178.64, mpid=11192, TLS, session=<N5V/0yVoSoRYQ6AP>

Domain1,2 und 3 liegen auf dem  selben Server. Und hier noch die komplette /etx/postfix/header_checks

# /etc/postfix/header_checks
# poor man's mailing list
/^To: .*bastelwastel@domain2.tld/ PREPEND Reply-To: bastelwastel@domain2.tld

Hier noch der Auszug aus dem mail.log, wenn es funktioniert, also wenn die Mail von einem anderen Server kommt.

Mar 26 22:24:07 mail postfix/smtpd[23829]: connect from mail-qk0-x229.google.com
[2607:f8b0:400d:c09::229]
Mar 26 22:24:08 mail postfix/smtpd[23829]: 04AD960C4D: client=mail-qk0-x229.goog
le.com[2607:f8b0:400d:c09::229]
Mar 26 22:24:08 mail postfix/cleanup[23832]: 04AD960C4D: message-id=<CAHAerZxh2k
UKfnguXbApOjuVx78XuT3SF=doL64UNhXCLYzDLA@mail.gmail.com>
Mar 26 22:24:08 mail postfix/cleanup[23832]: 04AD960C4D: prepend: header To: Was
tel Bastel <bastelwastel@domain2.tld> from mail-qk0-x229.google.com[2607:f8b
0:400d:c09::229]; from=<xxxxx@gmail.com> to=<bastelwastel@domain2.tld> pro
to=ESMTP helo=<mail-qk0-x229.google.com>: Reply-To: bastelwastel@domain2.tld
Mar 26 22:24:08 mail postfix/qmgr[6582]: 04AD960C4D: from=<xxxxxx@gmail.com>, s
ize=3142, nrcpt=6 (queue active)