3CX SMTP server error, not able to send mails

[delta-automat]

When testing the mail with 3CX SMTP I get this error. What could be wrong?

Error sending email. Response code: BadRequest, Response: {"Message":"Facility ID is invalid","Success":false}

 

[KyriacosS_3CX]

Hello,

Can you open a ticket with support, mentioning the correct licence key in the ticket? They should be able to assist in resolving this.

 

[Alphabetic]

Hello,
Was there any progress on this?

Solved Thread 'Issues with SMTP latest version'

Jun 17, 2026

I upgraded from V20 8 to the latest version

Noticed voicemails were not being sent as attachments using the 3cx smtp server, giving an error of

Error sending email. Response code: BadRequest, Response: {"Message":"Facility ID is invalid","Success":false}

I restored back to V20 version 8 and SMTP has started working again, I believe the update I upgraded to was version 8 secondupd (possibly the update after this)

• Mr F
• Replies: 10
• Forum: Phone System / PBX

 

[NikosT_3CX]

@delta-automat if you login to https://portal.3cx.com for this license key, do you see an FQDN assignt to it ?
Because if the FQDN has been released due to the fact that the key has not been activated for very long time,
then you will not be able to use 3cx SMTP and send emails.