PHP mail function

The function mail() from PHP may be used freely, in compliance with the law and our T&Cs.

We do not impose a limit on the number of emails sent in a given period but we limit their sending speed.

Thus, it is possible to send 20, 2000 or 20000 e-mails, without risk of being blocked, but they will be transmitted with a flow of approximately 600 e-mails per hour.

In case of abuse, we reserve the right to immediately suspend any site linked to an email that does not comply with the law or our terms of use.

Advice and optimization


The "From" (and associated headers: envelope-from, reply-to...) must always correspond to the domain name of the site from which the e-mail is sent.

Indeed, if the From of the sent email does not match a domain name associated with a Nuxit / PHPNET service, you are exposing yourself to a delivery problem caused by the SPF, DKIM and DMARC verification systems.

In conclusion, what not to do :

  • Use an email address entered by a visitor as a sender for a message sent via your website.
  • Use the e-mail address of another provider, such as, or as the sender.


  • Avoid using too muchimages in your email: try as much as possible to group several small images into one larger image. The image/text ratio must be balanced, in fact an email composed exclusively of images has every chance of being considered as spam. So think of accompanying your images with sufficient text. In general, put graphics, photos, logos... in short everything that is not textual. The textual part, as for it, must be typed in true HTML text. Last but not least, do not incorporate your images directly into the message, but link to images hosted on the web. You will get a double benefit because in addition to better passing the anti-spam barriers, you will lighten the weight of your message and at the same time increase the sending speed!
  • Ban Obviously, words or expressions with a double meaning that could have a sexual or "medicinal" connotation. Also avoid words like "Free", "Promotion", "Promo", "Discount", "Offer", "Sale", "Gift"... or certain characters, such as the exclamation mark or the question mark in the subject of the message. To find out which characters to avoid, you can visit the Microsoft site for Outlook. More subtly, avoid putting your hyperlinks behind terms such as "Click here".
  • The use of certain terms is not the only clue on which spam filters base their rejection of an e-mail. They also take into account the formatas the font size or its color. Thus, avoid writing the entire message in a font equal to or larger than 16. Also, red and green should be avoided.
  • Avoid as much as possible the files in attachmentsThis is especially important if your message contains little text. Instead, put your files on a web server and put download links in your email. By doing this, you reduce the weight of the message and therefore increase the speed of sending.
  • Even if you want to send your message in HTML format, also fill in the message part Text. You will get a double benefit: on the one hand, recipients who cannot read HTML (it still exists!) will still be able to read your email. On the other hand, anti-spam filters are generally less strict with messages in double format.
  • Don't put your URLs as IP addresses, and avoid URLs containing percentages and dollars. Don't put a tracked link behind a URL either. Instead, put something like "visit our site", or put your URL as an image.

Bulk sending

  • Each e-mail sent must mention a clear and functional unsubscribe link.
  • You must not send e-mails that to persons who have intentionally requested the reception of your messages.
Updated on 7 May 2020

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