Gmail pass authentication checks - email is blocked

Posted April 9, 2020 14.9k views

I’m using phpsendmail and when I run tests to gmail, I’m getting the following errors:

This message does not have authentication information or fails to 550-5.7.26 pass authentication checks. To best protect our users from spam, the 550-5.7.26 message has been blocked. Please visit 550-5.7.26 for more 550 5.7.26 information.

I’ve already added the TXT record to my domain in DigitalOcean dashboard.

type: TXT
hostname: @
value: v=spf1 ~all
TTL: 3600

Am I doing something wrong?

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2 answers

hi @srenert,

You’ll need to configure SPF and DKIM. Both of them serve as authentication so that other servers know your E-mails are legit.

SPF and DKIM are two types of TXT records in DNS that can help prevent email spoofing and ensure legitimate emails are delivered into the recipient’s inbox instead of spam folder. If your domain is abused by email spoofing, then your emails are likely to landed in recipient’s spam folder if they didn’t add you in address book.

SPF (Sender Policy Framework) record specifies which hosts or IP addresses are allowed to send emails on behalf of a domain. You should allow only your own email server or your ISP’s server to send emails for your domain.

DKIM (DomainKeys Identified Mail) uses a private key to add a signature to emails sent from your domain. Receiving SMTP servers verify the signature by using the corresponding public key, which is published in your DNS manager.

You can follow the following articles in order to configure it on your Droplet:

Once you have configured this, you can check this website for your E-mail score:


  • Thank you for the reply.

    I followed this guide:

    Afterwards, I ran the check on mail-tester, and got the following output. I think that means everything is correct, no? But when I try to send email to gmail, I still see the same error about it being blocked :(

    SPF check

    1 SPF record found for the domain :
    "v=spf1 ~all"

    DKIM check

    DNS record for
    "v=DKIM1; h=sha256; k=rsa; s=email; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyL2yfWY+i5WQxu11Wnyr1LjmAAkYU/1qB3H+9ei246iL3pHHhjutbknaxKodvijYQSkZJ1SsjbKoliyPxFi0aV78bMPTO5hW8DJhDwzTNjFIOFET7mkD/oq0tHYjeqZ+CgTMqLNAEz9w1IsWS85uX0QYu++xpr7YhjXkKwoFuC7Bk1F8IDocE9wK1+IxyU0bfCVzzrJZv27iwjBrN9jctBV2s4YuhSaCeJJqWMPNBiRio5tnkn3kms8Iu5OW3GbPj4tCgisFPJDl2CO6GwRZM6ZMG2BflMcvwmyavdQnogv+ICA5mIta277txU0F7igP/yvwx+Cxes7Onc0bCZiboQIDAQAB"
    Key length : 2048
    • The SPF record should be configured for the IP of your Droplet. It should look something like the following:

      TXT "v=spf1 mx a ip4:XXX.XXX.XXX.XXX -all"

      You’ll need to change XXX.XXX.XXX.XXX with the actual droplet’s IP and then add it as an TXT record to your domain.


I did everything, I added SPF and DKIM and still get the same problem.