Dear All, I have two machines, a Centos 3.4 machine and a Centos 4.1 machine. I have used the same sendmail.mc file on each, and 3.4 machine does plain SMTP auth with no problems, compiling the same mc file on the 4.1 machine gives this error: xxxxx [x.x.x.x] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA in the logs, it doesn't even try to authenticate, the cyrus sasl rpm is installed for auth PLAIN It reports this from the EHLO so all looks good: 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 250-DSN 250-ETRN 250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN PLAIN 250-DELIVERBY 250 HELP The 3.4 box reports this: 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE 250-DSN 250-ETRN 250-AUTH LOGIN PLAIN 250-DELIVERBY 250 HELP Any help would be greatly appreciated.... P.