How can I prevent my messages from falling into spam folder or being blocked by anti-spam?

Many of you ask us for advice to prevent your emails from ending up in your recipients' spam folders.
There is no such thing as a foolproof recipe, because the rules that define whether an email can be considered spam are both complicated and variable depending on the spam filters. That said, OxiMailing contains a very powerful anti-spam analyzer that gives you valuable insights into why your message is potentially classified as spam. The first thing to do is to start it by clicking on "Check & tests" and then on "Anti-spam analysis".


Then follow the recommended instructions and try to reach the ideal score of 0.


We also advise you to apply the 11 "golden rules" outlined below.


1- Systematically add a clearly visible and operational unsubscribe link. Don't try to hide this link by any method, an unsubscribe is a thousand times better than a spam complaint!

In a message, how to insert an unsubscribe link?


2- Avoid adding too many images in your email. The image to text ratio must be balanced, as an email composed exclusively of images is likely to be considered spam. Remember to include enough text with your images. In general, put in the form of images the graphics, photos, logos... in short everything that is not textual. The textual part, on the other hand, must be typed in real text. 
In a message, how to add an image?


3- Obviously, banish double meaning words or expressions that could have a sexual or "drug" connotation.
Also avoid words such as "Free", "Promotion", "Promo", "Discount", "Offer", "Sale", "Gift"... or certain characters, such as the exclamation mark or question mark in the subject of the message.
More subtle, avoid putting your hyperlinks behind terms such as "Click here".


4- Avoid attached files as much as possible, especially if they are pdf files and especially if your message contains little text. Instead, drop your files on a web server (or your OxiMailing Cloud space) and put download links in your email. By doing this, you reduce the weight of the message and therefore increase the sending speed. And another significant advantage, you will know thanks to the tracking who have downloaded the file (while you can't know who opened an attachment).

How do I send a file to the recipients of my message without attaching it?


5- The use of certain terms is not the only indication on which spam filters use to reject an e-mail. They also take into account the format, such as the size of the font or its color. Thus, avoid writing the entire message in font equal to or greater than 16. Similarly, red and green are to be avoided.


6- Do not put your URLs as IP addresses, and avoid URLs containing percentages and dollars. Do not put a tracked link behind a URL either. Prefer a mention of the "visit our site" style, or put your url in the form of an image. Another even better solution: use the customization function of the tracking url.

Why is it not recommended to put links in full text ( ?
Qu’est-ce que la personnalisation du tracking sur votre domaine ?


7- Use high quality HTML editors, such as the editor integrated in OxiMailing. Avoid tools like MS Word or Publisher that create a lot of useless and often non-standard code, making your message unreadable most of the time and increasing the chances of it being detected as spam.

Can I use an HTML page generated by Word or Publisher as a message?


8- Indicate in your message, ideally at the beginning, how you collected the recipient's address. For example: "You subscribed to our newsletter on the website" or "You receive this message because as a partner of Company X, you have authorized us to send you commercial emails related to...".
Or "You receive this message because your email address is published in the X file...".


9- Remember to qualify and maintain your address file. OxiMailing automatically and carefully manages the bounces generated by your mailings. It should be noted that the more emails you send to non-existent addresses, the more likely you are to be considered a spammer. Therefore, never delete your list of Bounces. Another good practice is to regularly remove non-reactive addresses from your files. To do this, the "360° view" available in the "Account" menu allows you to obtain a list of openers for all campaigns combined.


10- For each sending, make sure that your recipients' domains are as diversified as possible: to give an example, avoid absolutely too many aol or hotmail recipients, a high number of identical emails concentrated on the same domain can end up blocking or classifying them as spam. If your recipients' domains are not very diversified, then you should prefer to send them in several times, in smaller packages that are sufficiently separated over time. You should also know that there are "white-listing" programs available from most of the providers, which will allow you to reach a better result rate. Oxemis is a partner of Return Path and can therefore offer you to have your sendings certified.


11- Alwayse use an sender email address associated with your own domain name, for example (replace with your real domain name, of course, and make sure that this address exists!) Ban the use of hotmail, yahoo, aol, gmail or any other generic domain. Indeed, more and more spam filters check that an email sent with a GMail address (for example) has been routed with GMail's SMTP server and classify the email as spam if this is not the case.

Why should I not use a sender address in a "generic" domain?

How and why register a domain name with OxiMailing?


Finally, please be aware that it may happen that, even if you correct the above problems, you continue to receive the message in spam. Indeed, most spam filters are able to detect multiple mailings and end up classifying your message as spam simply because one mail in the series has previously been classified as spam... In other words, the correction will not change anything... for you. Indeed, this type of filter is usually applied to a single box, which means that you receive the message in spam while the other recipients will receive it in the inbox. Only solution, test on multiple mailboxes. 

In any case, do not hesitate to contact technical support by e-mail or phone! Our experts can analyze your message and give you precious advices to optimize them.

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