1) Do not send messages that your customers have not asked
2) Send content that is interesting and relevant to your customers
Even if you send the newsletter only to those who expressly asked to receive, ISPs are always aware of the interest that your messages generate in people. If they do not open and click on the newsletter, ISPs can filter it to the next spam submissions.
3) Clean your distribution list
Whenever you send your newsletter to disabled or invalid emails (typical behavior of spammers) ISPs can penalize you and block future shipments. Therefore, it is critical to remove from the list any addresses that are no longer being used (so-called bounces).
The MFORMULA MAIL email marketing platform makes cleaning soft bounces and hard bounces automatically and also inserts a link where people can click if they want to immediately remove from the list. The cleaner your list, more responsive and well behaved she is before the ISP and the better the direct delivery rate in the inbox.
4) Do not post content that get confused with spam
Before launching its newsletter, confirm that it will not make shooting all spam filters! Although each filter has its own rules, there are some general rules to follow.
• Do not send newsletters composed only of images (there must be a balance between HTML text and images)
• Use well-formatted HTML code (eg. Not create the HTML newsletter in Word or Photoshop)
• Prepare always an alternative version of the email in plain text
5) Make the senders and email servers
One of the things the ISPs are more aware is the server name through which you send the newsletter. To have a credible reputation, it is essential to authenticate your server with leading email certifications (SPF, SenderID, and DKIM DomainKeys). This process should be done by technical experts of your server.
6) Please note the frequency of shipments
Even if people want to receive your newsletter, may find excessive if every day and mark it as spam. On the other hand, it is less regular shipments (eg. Monthly), they may already have forgotten and consider it spam.
7) At the newsletter, ask people to add the sender to your safe list
Even following all the above tips, there is always the possibility that some too aggressive filters meddle your newsletter in spam.