Hello! There is a mail server that handles multiple domains and is responsible for sending confirmation emails from a forum. Unfortunately, these emails seem to be getting flagged as spam by Google.

I want to emphasize that emails sent from other domains, including newsletters with over 150k subscribed users, do not end up in the Google spam folder. The server already uses dkim and spf protocols to ensure email authenticity. Despite my attempts to modify the email content and subject, the issue persists.

I have been unable to find any information on how to contact Google support regarding this matter. Has anyone encountered a similar problem and found a solution?

The X-Mailer field, specifically stating "IPS PHP Mailer," can often flag emails as spam. This is because sending emails from a PHP script is generally seen as suspicious by spam filters, due to its widespread use by spammers.

To address this issue, one possible solution is to consider using third-party email services such as mailjet or elasticemail.com. These services can help ensure that your emails have a higher chance of reaching the intended recipients' inbox instead of being marked as spam.

Have you checked the IP history of your server using services like spamhaus? It's possible that malicious spammers have previously used your IP address, which could contribute to the emails being flagged as spam.

Additionally, it is important to consider the reverse DNS of the server from which the emails are sent. Does it clearly point to your domain or does it appear as something unintelligible like 19393.28.clients.someservice?

Aside from technical factors such as reverse DNS and SPF, the content of the email itself may also play a role. Take into account the text, links, their quantity, and where they lead. These elements can influence whether an email is marked as spam or not.

It's worth noting that ensuring proper IP reputation, having a valid reverse DNS, and carefully crafting email content are all crucial steps in avoiding spam folder issues.

I utilize the default postfix settings from PHP for sending emails. Currently, I send around 5k emails per day, and fortunately, none of them end up in the spam folder (fingers crossed). One important step I took was properly registering the PTR record and ensuring that the MX with the latest metric reflects this PTR record.

However, it is worth noting that services like Gmail and Mail.ru may not prioritize checking the PTR record, as it can be a resource-intensive operation for them given the amount of spam they receive. Therefore, in addition to proper PTR registration, it is crucial to craft unique and personalized messages with intriguing subject lines. It may also be beneficial to exclude images and HTML elements, or at least minimize their usage. Additionally, including clear instructions or a link for unsubscribing within the email's text can help improve its deliverability and avoid spam filters.

Remember, effective email deliverability relies on a combination of technical configurations and thoughtful message content.

It sounds like you are facing an issue with your mail server's emails being flagged as spam by Google. This can be a frustrating problem, but there are a few steps you can take to troubleshoot and potentially resolve the issue.

Firstly, make sure that your mail server is not listed on any email blacklists. There are various online tools available to check your server's IP address against these lists.

Additionally, you mentioned that your server already uses DKIM and SPF protocols, which is great. However, it may be worth double-checking the configuration to ensure everything is set up correctly. You can use email authentication checkers to verify the validity of these protocols for your domain.

If the issue persists, you might consider reaching out to Google's Postmaster Tools. This platform provides insights into how Google treats emails from your domain. It can give you valuable information about any potential issues or misconfigurations that may be causing your emails to be flagged as spam.

To contact Google support specifically, it can be challenging to find direct support channels. However, you can try posting in Google's Help Community forums or reaching out to their business support if you have access to such services.

Finally, keep in mind that improving email deliverability is an ongoing process. Algorithms used by email providers can change frequently, so monitoring your mail server's reputation and staying up-to-date on best practices is essential.

I hope these suggestions help you in resolving the issue with your mail server's emails getting flagged as spam by Google. Good luck!