Right now it's impossible to specify an arbitrary port in SMTP server Email media type. zbxmedia/email.c/send_email() assumes that incoming char *smtp_server doesn't contain any port definition as it's passed directly to zbx_tcp_connect() along with ZBX_DEFAULT_SMTP_PORT (25) port number.

I hacked together a simple patch to add recognition of standard colon port notation, but I'd like to know what would be the official zabbix way of improving this, is it enough to patch zbxmedia/email.c/send_email() to recognize colon port notation, or more complex changes are required (such as adding a separate smtp server port field to database and frontend)?