How to delist our email server from the blacklist

 

If your domain is a G Suite/Google Apps account, the domain administrator usually has access to  24/7/365 support from Google - see this page.   Non G Suite users, or users of free consumer "@gmail.com" accounts, cannot be helped by using that link. 

 

G Suite accounts can also use https://toolbox.googleapps.com/apps/checkmx/, and the helpful links there.

 

Otherwise, if some, all, or most of your emails to Gmail accounts are being classified as Spam, or being sent to Trash/Bin at the Gmail end, or Google are blocking your domain, or Google give a warning to the recipient, or if in some cases your mail is delayed before reaching Google at the last hop, or if (again in some cases) your mail is delayed internally at Google, you will need to comply with the Bulk Sender's Guidelines  at https://support.google.com/mail/answer/81126?hl=en&vid=1-635789122382665739-3305764358  (Note:  this page is badly named, it applies to ALL domains sending to GMail and G Suite accounts.)

In particular, pay attention to:-

 

Authentication & Identification
Subscription
Unsubscribing 
Format
Delivery
Third-Party Senders
Affiliate Marketing Programs

 

(these above links in blue are "clickable")

 

Changes to MX records may take up to 72 hours to filter through the Internet.

 

Also check your TLS  https://www.checktls.com/TestReceiver  Google require at least TLSv1.2

 

Sometimes, but not always, removing links from any signature can help.   Any URL's in the body of the mail which lead to insecure sites may need to be removed.

 

If the issue is with forwarded mail, you need to study  

If other Google users have marked your mail as Spam, Google will have learnt from this.  You need to get your mail marked as "non spam".

 

Gmail give the recipients (if a Gmail account) a banner message as to why the mail is in Spam.  You need to get the Gmail banner message from a recipient.  This message may have important clues for you.  Your mails will need to be marked by recipients as "Not Spam";  this is not an instantaneous solution, and may take some time for Google to acknowledge,  No way to speed this up.

 

Please also check your emails (both body and signature) for spammy content e.g. lots of exclamation marks; "must read"; attention getting, large and/or gaudy coloured text; text the same colour as the background; tiny text; [almost] zero height images; links hidden under text, images or links with a different URL; etc.  All or any of these may mark you as a spammer by Google.  Removal of links in signatures may also help.  Removable of clickable logos/pics in signatures may again be helpful.

 

There are  Postmaster tools to help you if a bulk mail sender:-  https://support.google.com/mail/answer/6227174?hl=en&vid=1-635789122382665739-3305764358, and Postmaster FAQ https://support.google.com/mail/answer/6258950?hl=en&vid=1-635789122382665739-3305764358

 

If your IP is marked as a Spam Hoster, you will also need to clean this up with your service provider.  Google maintain their own lists, but this posting certainly cannot help you.  Removal from a spam hosting list can take up to four weeks to filter through.  Even after that, Google may treat you account very cautiously, until proven as non spammer.

 

http://goo.gl/FQXdHx is helpful for bulk email senders and marketers. And this link https://www.unlocktheinbox.com/resources/emailauthentication/ can be very useful as well.

 

 

And, as a matter of interest https://support.google.com/mail/answer/1366858?hl=en helps recipients understand why mail is flagged as Spam by Gmail.  Also see https://www.whatcounts.com/2012/03/gmail-spam-warnings-and-their-meanings-for-email-marketers/

 

After doing all this, and the problems persist, you can use  https://support.google.com/mail/contact/msgdelivery All errors need to be corrected, before doing this.  Google may, or may not, reply.