If you do not know the e-mail address entered in the e-mail header under Return-Path, this e-mail may have been forwarded to another IONOSmailbox at your address.
If a IONOSmailbox forwards an e-mail, the IONOSmail system stores an encoded entry in "Return-Path" according to the so-called Sender Rewriting Scheme (SRS):
- By making an entry in the e-mail header, the SRS ensures that the original sender of a forwarded e-mail remains recognizable. Undeliverable messages can be sent to the original station.
- The entry is created according to the following pattern: SRS0=HHH=TT=hostname=local-part@domain, where HHH stands for a hash and TT for a timestamp. In the
following example, the e-mail was originally sent from the address firstname.lastname@example.org: