Error, when e-mailing invoices

Suddenly I reveive an error message, when e-mailing invoices to customers. This has never been a problem before: Does anyone know what is causing this?

The message is a number of lines with all sorts of numbers. First line reads:

“System.Net.Mail.SmtpException: System.Net.Mail.SmtpException: 535 5.7.0 Mailgun is not loving your login or password”

search the forum. everything has been discussed already and solutions given.

I did indeed search the forum, before creating this topic, but was unable to find a solution. Would this hvae enything to do with settings on my computer or my Manager settings? All I know, is that suddenly I receive an error messege trying to do something, I have done without problems.

Have a look at

and Forum smtp category

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