yum install sendmail sendmail-cf

# vi /etc/mail/sendmail.mc

TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl

define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl

DAEMON_OPTIONS(`Port=smtp,Addr=0.0.0.0, Name=MTA')dnl

# m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf

systemctl start sendmail.server



yum install sendmail sendmail-cf

yum install dovecot cyrus-sasl cyrus-sasl-md5 cyrus-sasl-plain cyrus-sasl-lib

TRUST_AUTH_MECH(`EXTERNAL DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl

define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl

define(`confAUTH_OPTIONS', `A p')dnl

define(`confCACERT_PATH', `/etc/pki/tls/certs')dnl

define(`confCACERT', `/etc/pki/tls/certs/ca-bundle.crt')dnl

define(`confSERVER_CERT', `/etc/pki/tls/certs/sendmail.pem')dnl

define(`confSERVER_KEY', `/etc/pki/tls/certs/sendmail.pem')dnl

DAEMON_OPTIONS(`Port=smtp,Addr=0.0.0.0, Name=MTA')dnl