Thanks Neol you cleared my big confusion i thought 25 is for MTA and 587 will never receive email from MTA. thanks for that.
now one last question. my master.cf has set -o smtpd_tls_security_level=encrypt it is said that when parameters are set in master.cf they override main.cf parameter. now i set. main.cf parameters. smtp_tls_security_level=may smtpd_tls_security_level=may i believe that if master.cf parameter set as "-o smtpd_tls_security_level=encrypt" it should throw the same error as if this parameter set in main.cf however now my mails are properly working and master.cf not overriding it. can you please throw some light on this. Thanks, Yousuf
