We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Why do some of my contacts not receive my emails?

  • 1 reply
  • 1 has this problem
  • 5 views
  • Last reply by Matt

more options

Some of my contacts can't receive my emails. I get the following error messages:

"Remote host said: 553 5.1.3 bad address syntax"

"Remote host said: 501 Invalid Address [RCPT_TO]" "Remote host said: 501 Syntax error in parameters or arguments [RCPT_TO]"

I have talked to them personally and they say they aren't trying to block my messages.

The email addresses involved never used to give me a problem. Now it's every time.

Some of my contacts can't receive my emails. I get the following error messages: "Remote host said: 553 5.1.3 bad address syntax" "Remote host said: 501 Invalid Address [RCPT_TO]" "Remote host said: 501 Syntax error in parameters or arguments [RCPT_TO]" I have talked to them personally and they say they aren't trying to block my messages. The email addresses involved never used to give me a problem. Now it's every time.

All Replies (1)

more options

are you requesting return or read receipts?