Error sending email to my disroot

Hi there! the last few days I’m receiving an error message while send an email from a certain mail address to my disroot email. This is the error message:

Sender address rejected: Need to login (in reply to
RCPT TO command)

Diagnostic-Code: smtp; 554 5.7.1 user@domain: Sender address
rejected: Need to login

Anyway I still receive the message but the sender receives the error above. Also the the automatic forwarding of any messages that I have set doesn’t work. I encounter this error only when the sender belongs to a specific server. This server have had a troubled upgrade in the last days that probably is part of the problem. Any idea on how can I solve this? I can send more details if needed. Thanks a lot. R

It looks like it could be an issue with the other service provider. Perhaps you want to send message to support_at_disroot.org so we can more freely share more details and follow up on this.

Sure. I just sent an email. Thanks