Disadvantages using of SMTP Additional administrative overhead Creates need to set up security, i.e. firewall Requires expertise Your choice should mainly depend on the know-how that is available within your company. If you feel you can deal with the additional administrative overhead of using SMTP, select SMTP. If on the other hand you are not sure that you have the know-how in house to configure SMTP, DNS servers, Firewalls etc., it is best to go for the POP3 option and accept its limitations.