When using email services regularly, you quickly face a crucial question: how do you prevent your email from being flagged as spam and ending up in your recipient's spam folder or trash?
This question is increasingly important as anti-spam solutions and filters — along with internet security measures — continue to evolve and become more robust.
To avoid landing in your recipients' spam folders, several factors come into play; specifically, you must pay attention to your message's subject line and content, and properly authenticate the senders for emails originating from your domains.
Discover some best practices here for bypassing anti-spam filters, reducing spam reports from recipients, and improving your email deliverability.
1. Sender name and email subject line: always use the same sender name and choose your subject line carefully.
2. Email content: pay attention to images, formatting, the words used, and attachments (content and format). Never include attachments in emails sent to mailing lists or in marketing emails.
https://www.blogdumoderateur.com/mots-spam-mail/
https://www.mailjet.com/blog/email-best-practices/spam-words-to-avoid-in-email/
https://www.mailjet.com/fr/blog/delivrabilite/redefinir-le-spam/
3. An unsubscribe link for your distribution list is MANDATORY.
(Note: Google and Yahoo now enforce a set of sender requirements that determine whether your mail is accepted or rejected. Here is the complete, up-to-date checklist for 2026 Deliverability Google and Yahoo sender requirements by Qualisend — SPF, DKIM, and DMARC, one-click unsubscribe, a spam complaint rate below 0.3%, valid reverse DNS, and TLS — along with the required action for each point).
4. Email HTML code: use only high-quality code.
5. Reputation of the sending server’s IP address and the sending domain: watch out for blacklists. Choose your sending domain and email marketing solution carefully.
Helpful tools and resources:
- https://www.mail-tester.com/
- https://mxtoolbox.com/c/products/deliverycenter
- https://glockapps.com/
- https://senderscore.org/
- https://email-spam-tester.com/
For more information and a detailed guide by Cakemail: https://www.cakemail.com/blog/post/the-complete-guide-to-avoid-being-marked-as-spam