Email not getting received in Yahoo, MSN

I have successfully configured my Mail-in-a-box server. However, I can only send emails to Gmail. Emails sent to Yahoo, MSN, Outlook are not received. What can be the issue?

Try to find the log message for the failed email in /var/log/mail.log.

Can this occur because of IP blackisting from Yahoo and Outlook?

It can be many things. Usually they include these kinds of reasons in their server responses that get put in the logs.

Okay. Thank you!. I’ll access the logs

This is the output of the logs received from /var/logs/mail.log . The error received once I send a mail to Yahoo is:
host[] said: 421 4.7.0 [TSS04] Messages from temporarily deferred due to unexpected volume or user complaints -; see (in reply to MAIL FROM command)
lost connection with[] while sending RCPT TO
setting up TLS connection to[]:25

The output of log received once I send a mail to outlook is:
JPNP286.PROD.OUTLOOK.COM>: stored mail into mailbox ‘Spam’

I don’t see the IP address showing up on any blacklists.

I do see that you don’t have PTR/rDNS record configured for the IP address. It may be that you are in an IP address range that gets more scrutiny, so you might want to make sure you have no errors reported by MiaB in the dashboard, as the finer points there are for proof-of-work to ideally pass all these tests.


If you want to deliver email to Verizon, you better have rDNS configured.

I have got my rDNS configured. It can be verified from MX tool box. Even after configuring rDNS, I am still not able to send mail to Outlook. I am getting a bounce email that shows that my IP is blacklisted. How can I get it resolved from Outlook? @alento

Please post any error currently showing in the MiaB dashboard.

This should help:

Setting up an SMTP relay solves the issue. I configured Sendinblue as an SMTP. My mails are now getting received in Outlook and Yahoo. However, they are still landing in Spam box.

Probably because spammers are using these services too… I think your domain has to build up some reputation first. If users unmark your emails repeatedly, they will most likely end up in their inoxes after a while… That was at least my expirience with I never had to use a service like Seninblue though in the first place. Not sure if using such a service generally makes things harder or easier with, to be honest.

Well, at least it allowed my mails to deliver successfully. I think you are right that the mails can ultimately land in inbox if they get repeatedly marked as safe from my recipients. Thanks for the input!

Indeed, spammers use the free services too!

You really need a paid service unfortunately. More here: