This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

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

Every time I send an email to a particular person, it fails to send. Why?? only happends to this one address.

  • 1 reply
  • 1 has this problem
  • 3 views
  • Last reply by christ1

more options

Every time I send this person an email, it is returned as "Mail Delivery. Is this person blocked? Is the problem on my side or her side? Here is a shot of the failed delivery:

SMTP error from remote mail server after end of data:

   550-DKIM: encountered the following problem validating fbcinfo.org:
   550 pubkey_unavailable

Diagnostic-Code: smtp; 550-DKIM: encountered the following problem validating fbcinfo.org:

550 pubkey_unavailable

Help!

Every time I send this person an email, it is returned as "Mail Delivery. Is this person blocked? Is the problem on my side or her side? Here is a shot of the failed delivery: SMTP error from remote mail server after end of data: 550-DKIM: encountered the following problem validating fbcinfo.org: 550 pubkey_unavailable Diagnostic-Code: smtp; 550-DKIM: encountered the following problem validating fbcinfo.org: 550 pubkey_unavailable Help!

All Replies (1)

more options

It is a problem between your email provider and the recipients email provider. Talk to your email provider. This has got nothing to do with Thunderbird.