ERROR_CODE :550, ERROR_CODE :5.7.1

ERROR_CODE :550, ERROR_CODE :5.7.1

I have problems with some emails, especially wth " @pl.hanze.nl" . See the text below. Yesterday I updated my DNS records with the SPF TXT code. Still I have the same problem.

I hope you can help


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 d.c.witte@pl.hanze.nl  Invalid Address, ERROR_CODE :550, ERROR_CODE :5.7.1 Recipient not authorized, your IP has been found on a block list 


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To:"Dineke" < d.c.witte@pl.hanze.nl > 
Subject:Re: Schrijven, het moet! 
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