Email error 550 – Please turn on SMTP Authentication in your mail client

Ever get this error when trying to send an outgoing email?

When you read the error it makes you think there is something wrong with your email client.  In my case Thunderbird.  By default your email client should have SMTP Authentication turned on so it is unlikely that. It could be the culprit but it would have been something you would have noticed by now if you used any kind of gmail or yahoo account.

If you think it may be your client then you check by going into the properties or settings in your email client.  Find the settings for that problem email account and look for the “Outgoing Server” settings.  You will want to make sure you do not see a “No Authentication” selected anywhere.  Or any checkbox that may say “My Server Requires Authentication” should be checked.

If you found this it is very likely you are configuring a new email server or just changed MX records for an existing email account.  If you just tinkered with MX records or DSN settings then there is likely something wrong with your spf entry.

For me I was changing DNS settings in Web Host Manager so a client could use Microsoft Exchange for their email hosting while I still host their website.  Turned out that this error is because gmails email server looks for Sender Policy Framework SPF entries to protect spam traveling through their system.  I originally had the spf TXT entry in my DNS settings entered as follows:

Then I had to change one character.  You may need to change the “-” to “~” which is sometimes the culprit.

You can also play around with including it inside of quotations or not.  Also make sure there are not any other spf entries or that could be a problem as well.

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