Problems caused by inconsistent email sending address and reply-to address


we have a tricky issue here regarding the email service in our journal’s workflow. We have it set up to use a specific email address configured in the backend (e.g., However, in practice, specific roles operate within the workflow and send emails to other specific roles. When these emails are sent out, the sender’s email address is, but the reply-to email address is the personal address of the role sending the email. This inconsistency causes the email server to detect it and intercept the emails (the backend error code is: 550 5.7.1 [ZLQ] Blocked). We consulted our email service provider, and they mentioned that the address mismatch must be resolved. My question is, do you have any solutions for this issue?

We are using OJS version

Hi @jicai.he

In your scenario, this could not seem to be the cause of SMTP error 550 5.7.1.

But use of fake email addresses might have caused your server IP or domain to be blocked by spam filters. That is a common condition for shared hosting servers.
Please look at that pages and try to follow instructions on it;

and check if your email server meets some requirements such as DKIM, DMARC and SPF.
You may check the spam score of your mails here;

The following is a good site to check if your smtp server’s ip has been blocked;
You may also share true postmaster’s message so that we may understand the logic behind the block.