What is SPAM, how does it work and how can I prevent it?

In this article you will find some tips to prevent your mail from being marked as SPAM. SPAM stands for SendingPeople Annoying Mail.

First of all, it is important to know how spam marking works. For simplicity we will take the number 100 as the tipping point when something will or will not be marked as spam. So everything below the score of 100 is good and will not be marked as spam and everything above it will mark the mail as unwanted.

Now every mail you send is checked by a spam filter which then assigns points to it. The spamfilter checks for example for sender, subject, the text in the mail, are there any attachments, what kind of attachments and many more criteria. The mail address info@mijnhostingpartner.nl for example gets 1 point but the mail address Jokjonhhu9sdnk@hotmail.com gets 10 points. If the subject contains "hello" then it gets 1 point but if it contains "here cheap viagra for sale" then it will be awarded more points.

When all the points of the criteria added together reach the tipping point of 100, the spam filter will mark the message SPAM. Many of these filters work with different spam rating levels. For example a message between 100 and 150 points will be marked SPAM-LOW, a message between 150 and 200 points will be marked SPAM-MEDIUM and everything above 200 will be marked SPAM-HIGH.

At MijnHostingPartner.nl we work with such a marking. If you receive a lot of mail that is marked as SPAM then you can use the webmail rules to set what you want to do with this mail. For example you can indicate that you want mail marked as SPAM-HIGH to be bounced by the mailserver and that you want mail marked as SPAM-MEDIUM and SPAM-LOW to be placed directly in the junk folder. How you can do this can be found in this article: https://www.mijnhostingpartner.nl/client/knowledgebase/214/Hoe-stel-ik-de-SPAM-filter-in.html.



Do you need an extra verification layer next to the SPAM filter?

Then you can also add the DKIM option.

When this is set the receiving mailservers will check the email message again for authenticity. This way an extra authentication layer is added.
How to set this up you can read in the following article: https://www.mijnhostingpartner.nl/client/knowledgebase/815/DKIM-en-certificaat-sleutel-instellen.html

Now that you know a bit more about how a spam filter works it might be easier to understand how to prevent this. Here are some tips.

Headers (source of the mail message)

• The sender (from) address should actually be the sender address. This is one of the reasons that MijnHostingPartner.nl uses smtp verification for outgoing mail.
• Spammers often try to hide the sender and destination. If you try this then your email will be seen as SPAM by the filters.
• If you add unnecessary headers to your message it is more likely to be considered SPAM.
• Use the correct date/time format in the headers. This also often depends on the mail server you are sending from. If you send via the webmail of MijnHostingPartner.nl then you can assume that the date and time is correct. This is synchronized with the atomic clock.

Domains

• Use a domain that exists and has a valid IP address. This applies to both the sender's and recipient's mail addresses, as well as the reply-to address.
• Use SPF identification in DNS records. MijnHostingPartner.nl already uses this automatically and prevents spammers from successfully impersonating your identity (email addresses of your domain).

Mail programs and formatting

• First of all, use a mail program and tools that work correctly. Properly formatted emails (technically correct) are rarely noticed as SPAM. Mails with missing mime sections, incorrect or missing message-ids and/or date headers, subject and/or other headers with unescaped unicode for example are often marked as SPAM.
• Avoid unnecessary encoding. For example, do not use base-64 encoding unless it is really necessary.
• Do not use a disclaimer at the bottom of your message stating that your message is not SPAM or meets all SPAM requirements. This is what SPAM messages do.
• If there are certain rules about sending mail, it is better to stick to them. For example, if you send a message to more than 25 users at once, you run the risk of these messages being marked as SPAM.
• Use normal language. Do not use extreme amounts of spaces in the message, capital letters in the subject or excessive use of exclamation marks. Unusual characters in words can also contribute to a spam marking (e.g., M@rk3ring, Sp2mf!ltrrr).
• Further, avoid certain topics in your mail such as viagra, sexually oriented items, Rolex watches, drugs or medical treatments. With a combination of these words, a message is usually counted as SPAM, even if everything else is fine.

HTML

• When sending HTML messages use a good html editor. It is advised to avoid the use of MS Word. This program often leaves empty html tags such as "". Empty or incorrect tags will result in a higher spam mark.
• When you use a title tag in HTML, make sure it is relevant. Programs such as Dreamweaver and MS Word will leave the title blank or put 'untitled page' or 'nameless' in here.
• Avoid invisible text in HTML code, use normal size text.
• Avoid programs to track HTML e-mails. When you do want to follow a mail message, do it visibly in the html.

Other tips

• Do not send large amounts of mail with the same message and/or subject.
• Be careful with possible advertisers in your e-mail messages. Some URLs are included in a blacklist.
• If you send a mailing, it must by law always have an unsubscribe option. If it is not there, the recipient may decide to report it to a blacklist.
• Analyze your own spam folder. You can learn a lot from this about how NOT to do it. Look at the design, content and structure of the HTML code.

If you have any more questions about SPAM and how to prevent it, you can always use the chat on our website. Our colleagues are of course willing to answer your questions in the best possible way.
Any tips for this article? Report it via our chat or ticket system and we will look into it.

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