The best solution for sending communication emails from PrestaShop is to use an SMTP server of an email account . The use of paid or free emails, for example GMAIL, raises several problems due to the limitations of sending. These emails are configured for personal use by an email client and to combat abuse of use and reduce the risk that they are voluntarily or involuntarily used for SPAM activities the hourly sending limits are very limited . To worsen the situation, many providers (for example Aruba) use third-party services to verify that the sending via SMTP is carried out by a reliable IP and that the request is not suspicious, the control takes place through heuristic analysis and consequently we often find ourselves to deal with false positives. This is done to prevent, above all, that massive SPAM emails are sent due to an infected system.

There are also problems related to sending to GMAIL accounts (related to IPv6) that often afflict Aruba email accounts or related to the SSL certificate, especially when it is a Let's Encrypt which, although excellent in case it is used for email, encounters problems compatibility.

This unfortunately is a problem for ecommerce that receive many orders and / or use modules such as Follow-up or similar to send promotions or invite customers to complete the order (abandoned carts) if for example our provider has set the limit of hourly sending at 40 emails / hour and the daily maximum at 200 emails sent, each email following those limits will be blocked by the server and will not reach its destination. And very often when PrestaShop exceeds the sending limits set by the provider, the same either blocks email accounts for suspicious SPAM or blocks IPs from which the request comes.

It is clear that using these emails to send communications to customers from your ecommerce is not an advisable solution.

For this it is necessary to use emails dedicated to the purpose.

Find out the score of your Email

The first thing to do is to check the score of your email through the mail-tester.com service
To do this from BO go to Advanced Parameters -> Email
Go to: " Test your email configuration " and enter the email shown by the mail-tester in the appropriate field and click on: " Send a test email ".

Sending limits per hour and per day

Even if the email score is perfect, it can still happen that it does not arrive at its destination, the main cause is in the hourly sending limits. If PrestaShop has to send 100 emails to invite customers to complete the order and the SMTP server time limit is set at 40 emails / hour, 60 emails will not reach their destination.

UCEPROTECT and IP ban problems

Even when we have configured our email server to perfection, it can happen to have problems sending to some free accounts including the Italians: libero.it, virgilio.it, alice.it, etc ... often the problem lies in the fact that the our IP is in the backlist on UCEPROTECT , or more precisely some IPs of the class to which our IPv4 belongs have carried out spam activities. That is, we are not directly on the list of IP blocked, but due to activities beyond our control we are indirectly.

UCEPROTECT, is a network that operates with very restrictive principles (in our opinion even out of time), and works with level-based filters.

  • Level 1 concerns the single IP. It is often more and more common to have a shared IP, in which case even if we behave well, someone else using the same IP may not. This is why it is very important to use a dedicated IP for the email server.
  • Level 2 covers the entire IP class (approximately 65,000 addresses for class B).
  • The third level is the most serious, it concerns the whole provider.

The most common case is level 2 , that is, from one or more of the 65,536 IPs to which our IPv4 belongs, has made spam activities, it can happen in these cases that by sending an email to an address or to the addresses of a manager mail, it ends up in the recipient's spam or is rejected by the mail server. You can check your dedicated IP here: http://www.uceprotect.net/en/rblcheck.php

Despite having a lot of budget today it is impossible to get an entire IP class, the last block of IPv4 was assigned by ICANN in 2011. The only solution is to ask (against payment) to UCEPROTET to add our dedicated IP to the Whitelisted ( http://www.whitelisted.org/ ) in this way we would be safe from blocking our emails due to levels 2 and 3 of the UCEPROTECT filter.

These are rare events, but sometimes cyber attacks and viruses can lead to the unconscious sending of spam or dangerous emails by multiple users of a provider, the probability that an IPv4 of the class that our dedicated IP belongs to is reported is very high, there are also services that allow you to monitor these events, such as: https://mxtoolbox.com/blacklists.aspx

Author: Loris Modena

SENIOR DEVELOPER

For Ind Loris Modena , owner of Arte e Informatica , he began working in the IT sector in 1989 as a system engineer in charge of the maintenance and installation of IT systems. He started programming for the web in 1997 dealing with CGI programming in PERL and then moving on to programming in PHP and JavaScript. In this period he approaches the Open source world and the management of Linux servers.

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