Been there, done that. After a bit of back and forth, Telekom basically recommended that I go and use one of the big SMTP servers and stop bothering them. While I hated myself for doing it, I eventually switched to Gmail for peace of mind.

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bayindirh an hour ago | parent [-]

This is one of the reasons why I'm not planning to host my own e-mail server. It's not that I can't do it, but I don't want to sink time into investigating and working around/solving things like that.

	▲	Avamander an hour ago \| parent [-]
		The small boutique mail hosts are also much more tedious to deal with than any of the big players. So it depends on your recipients how much effort self-hosting is.