Issue Emails are not delivered nor received

[Patashoow]

I changed the MX records to use Ionos server and it didn't resolve the problem. Again, I don't know if I did it correctly as I only changed DSN records.

One interesting point, is that when I use Ionos webmail (with mail services that run on my server), the email is sent to Hotmail but marked as spam but when I do it directly from a PHP script, it bounces back with the same issue.

Any idea about the reason?

 

[Bitpalast]

Changing the MX records to another server does not change anything about sending mail. You are still sending your mail from your own server. To send mail through another server, you need a login there and will need to send mail through that external server by logging in and submitting mail for transport just as if you do through an email client.

Besides, using mass service mail servers will probably not solve anything, but it will make things worse. Because on these systems millions of outgoing mails are processed. And there are always some users who spam, so such mass mail servers are blacklisted over and over again. You'll notice the same with GMX, web.de, Yahoo, Freenet, T-Online etc. Ionos, GMX and web.de are basically the same thing. So again: This does not help your case. You need to find out why your IP from where you send mails is blacklisted.

 

[Patashoow]

Changing the MX records to another server does not change anything about sending mail

Ok thank you for the precision, that's what I thought. So it's clear now that it's not the solution I'm looking for.

You need to find out why your IP from where you send mails is blacklisted.

I checked again the link that you provided last time and it says "blacklisted: 2" for those two:

vote.drbl.gremlin.ru​

work.drbl.gremlin.ru​

Should I give a big consideration to that?

Again, with Mxtoolbox, everything is absolutely right (0 errors, 0 warnings).

Also, as I've mentioned, when using Ionos webmail, the emails are sent to Hotmail but marked as spam. But when I use Roundcube or PHP script, they're not sent at all.

So where should I look to solve this?

 

[Bitpalast]

I think that Microsoft would be the right place to ask for help. If you are sure that your server is not sending spam, they ought to unlist you. Are you sure that you understood their mail to you correctly? Sometimes they respond to a case with something like "... does not qualify for mitigation", and then you will need to respond to that mail again to get a human on the line (email) to take care of the case. Else it is pretty much automated there.

 

[Patashoow]

I think that Microsoft would be the right place to ask for help.

I've searched on the internet somewhere else I can get in touch with them for that kind of issue and it seems that the only way of doing so is to go through the form that I've already submitted.
I've also seen that it may take up to 5 days for the changes to be applied.

Are you sure that you understood their mail to you correctly?

The mail is pretty straightforward and just says

Dear ******

We have completed reviewing the IP(s) you submitted. The following table contains the results of our investigation.

Mitigated
*.*.*.*
Our investigation has determined that the above IP(s) qualify for mitigation. The block has been lifted, and the IP(s) have been granted increased daily sending limits. Please note that this does not guarantee that your mail will be delivered to a user's inbox. This mitigation only means that mail from the above IP(s) will no longer be throttled until it exceeds its new limit.

Outlook.com limits the number of email messages a particular IP can send within a time period based on the IPs reputation. When an IP exceeds its sending limit, any further SMTP commands from the IP will receive error code 421 from Outlook.com and the connection will be terminated.

And then they recommend to use JMRP and SNDS.

I'm still wondering why emails sent from Ionos webmail are sent as spam but those from Roundcube or scripts bounce back.

 

[Bitpalast]

but those from Roundcube or scripts bounce back.

That's probably due to a missing entry in your postfix configuration file. When you send a mail from a webmail client, the sender IP is 127.0.0.1. This does not match your public server IP. It leads to a false assessment at the receiving mailserver that the IP of the sender does not match the PTR entry for the host. To avoid that issue, you need to add a line to your /etc/postfix/postfix.main.cf file and restart postfix:

myhostname = <your hostname here>

Then
# service postfix reload

 

[Patashoow]

To avoid that issue, you need to add a line to your /etc/postfix/postfix.main.cf file and restart postfix:

myhostname = <your hostname here>

This line already exists and its value is correct.

 

[Bitpalast]

What is the exact error message from the bounced mails? Is that the blacklist message?

 

[Patashoow]

Yes it's the message that I've posted here.

 

[Bitpalast]

O.k., I see. But this is again pointing back to an issue at Microsoft systems. I doubt that it can be resolved without their help. At least after all these posts.

 

[Patashoow]

I'm checking right now for some solutions and will post updates if any for those who would meet the same issue.
Thank you again for your help.