Using the Alpine Linux email client to access messages from any network
Sometimes when I’m traveling, I have trouble sending email from my devices that typically connect to my ISP at home via hardwire or WiFi. This is because some ISPs do not like outbound email to leave their network unless it is routed through their own email servers. But you need to have an account with the ISP in order to send outbound email through their servers.
This intentional blocking of outbound port 25 for email is usually aimed at preventing hijacked hosts from acting as spambots and sending email over the ISP’s network.
Read about how I circumvented that problem.