As of V8.10 sendmail, support for SMTP AUTH can be included by defining this SASL compile-time macro. SMTP AUTH is defined in RFC22554. For V8.10 and above, sendmail provides that support using the SALS mechanism (see Section 10.9 for complete instructions).

To enable support for SMTP AUTH, define this SALS macro in your Build m4 file like this:

APPENDDEF(`confENVDEF', `-DSASL')

If you are running a precompiled sendmail binary, you can use the -d0.10 debugging command-line switch (-d0.10) to determine if SASL support is defined (if it appears in the list, it is defined).