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Diego
Asked: 2020-07-22 22:47:11 +0800 CST 2020-07-22 22:47:11 +0800 CST

How can I configure my server to send mail correctly?

  • 772

I have a server in which the user requests to register in a portal and I send an email with the data.

This email always reaches spam, but it is an email with a username and password, nothing more.

How could I configure the server so that it reaches the inbox?

It is an Ubuntu Server 15.10.

ubuntu

3 Answers

  1. Best Answer

    I recommend you to use Email Server Test , which is a perfect tool for this kind of cases.

    Basically you send an email to [email protected]and they reply with a detailed report of what is going on (and it will be easy to solve). What this tool looks at is:

    • HELO Greeting - If you have a problem here, check out this link .
    • Reverse DNS - If you have a problem here, check out this link .
    • DNSBL (RBL) - If you have a problem here, check out this link .
    • SPF - If you have a problem here, check out this link .
    • Domain Keys - If you have a problem here, check out this link .
    • SPAMAssassin Content Checks - If you have a problem here, check out this link .
    • BATV (Bounce Address Tag Validation) - If you have a problem here, check out this link .
    • Greylisting - If you have a problem here, check out this link .
    • URIBL - If you have a problem here, check out this link .

    Also, as Jordi Castilla indicates , you can check in MXtoolbox if your IP/Domain is on a blacklist (although the BlackList and the GreyList are already checked in the previous section)

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  2. There may be several reasons why an email arrives in a SPAM box instead of in the inbox without being included in any blacklist.

    • Violation of email security policies (SPF, DKIM and/or DMARC): If you use an email account from a domain that uses this type of security as the sender, when it reaches a recipient it will recognize that your server is not a server trusted and will mark it as SPAM. For example, gmail, hotmail, live, yahoo, etc use these protections, you cannot use direct sending of emails from these domains from your own server. Solution: Don't use the mail()PHP function, use a library like PHPMailer that supports sending by SMTP/S and configure the outgoing server of your mail provider, don't use the MTA of your web server.
    • Violation of any of the RFCs related to SMTP and/or MIME: If you do not use the correct headers, if you do not use the correct character encoding, correctly form the SMTP message, etc., you can be "detected" by anti-spam applications as a SPAM message. Solution: PHPMailer could help you with this issue, you indicate the HTML, the version of the content in plain text, the additional headers you want to use and it assembles the message correctly.

    If you know how to use spamassasin, I would recommend passing a lint to an email message you have sent to find out what anti-spam rules you are complying with in order to try to fix or avoid them.

    I'm sorry, but without code or example of the mail content or any other information I can't help you further.

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  3. By not giving many details of how you are doing it, it makes me assume that you are sending the emails by mail(), if so, a good function to send emails and not get spam, is to use PHPMailer Github , your emails would be sent with authentication and using SSL, avoiding reaching the SPAM folder.

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