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Verizon is blocking port 25 - check your email clients

Verizon is blocking outgoing port 25 (often used as default for smpt outgoing email).

This will manifest as a strange problem of Thunderbird or other email client being unable to send messages but receiving them just fine when you are at home, and showing no symptoms when you are at work (if they don't have Verizon at work).

To rectify this simply change the port on the outgoing server to 587.

Of course, what happens when spammers start to use port 587?

Further reading here.

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