if SMTP server needs authentication
SMTP server authentication is not the same as POP3 and IMAP, you need to encode your user and pass as one and use the AUTH PLAIN command before sending the email when using TELNET. You can use a PERL command to generate this. Perl needs a backslash before any strange characters like @ and \000 before the user and password.e.g.
perl -MMIME::Base64 -e ‘print encode_base64(”\000user\@domain.com\000pa\$\$word”)’
Which would result in something like;AHVzZXJAZG9tYWluLmNvbQBwYSQkd29yZA==
Use this encoded user and password then with the
AUTH PLAIN AHVzZXJAZG9tYWluLmNvbQBwYSQkd29yZA==
command after the HELO command as above…