With the introduction of sendmail V8 for Solaris 2.x in patch form and in Solaris 2.5, a bug in sendmail.cf has suddenly started to play up. The end-of-line character is not defined for the ethernet mailer, causing sendmail to send bare newlines in violation of the SMTP protocol which requires CR-NL.To fix, find the following line in sendmail.cf:
Mether, P=[TCP], F=msDFMuCX, S=11, R=21, A=TCP $h
and change it to:
Mether, P=[TCP], F=msDFMuCX, S=11, R=21, A=TCP $h, E=\r\n
To be on the safe side, check all lines starting with "M" that contain P=[TCP] or P=[IPC]. They all should use "E=\r\n".
This bug is also fixed in the latest Solaris 2.x sendmail patches.