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how_to:sender_domain_must_resolve [2018/11/14 10:45] (current)
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 +======Sender Domain Must Resolve======
 +If you receive an 'SMTP Client Error' something like:
 +''​451 ( Sender Domain Must Resolve''​
 +this means that the ISP's mail server cannot find the part of the email address.
 +Often this means that the FROM address of the message is invalid, or that the ''​Settings -> Local Mail -> Default Domain''​ is incorrect. This setting should always be a valid Internet email domain.
 +Occasionally this can happen if you have just registered a new domain (or moved the domain to a new ISP) as the DNS entries for the domain can take a while to propagate to all DNS servers, so the mail server may be talking to a DNS server which doesn'​t recognise the name yet - in this case waiting a few hours may cause the problem to rectify itself automatically.
 +If you know that the FROM addresses you are using are correct, try contacting the ISP to get them to check their settings - it is not unknown for their servers to be set up incorrectly. ​
 +{{tag>​SMTP client error_code domain resolve send}}
how_to/sender_domain_must_resolve.txt ยท Last modified: 2018/11/14 10:45 (external edit)