Usually, the port used for the Outgoing Mail Server/SMTP Service is 25. However, there might be a situation where your ISP might be blocking the use of port 25 for SMTP service. To circumvent this you can use an alternate port 587 for sending mails.
Usually, the port used for the Outgoing Mail Server/SMTP Service is 25. However, there might be a situation where your ISP might be blocking the use of port 25 for SMTP service. To circumvent this you can use an alternate port 587 for sending mails.