What should you do if you receive this error message when sending emails from Belcofin?
Please check the following:
You can find it via this link: https://docs.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/authenticated-client-smtp-submission
You should find a solution: it says there that most programs do not use AUTH, so you must use a mailbox where that setting is off.
Virtually all modern email clients that connect to Exchange Online mailboxes in Office 365 or Microsoft 365 (for example, Outlook, Outlook on the web, iOS Mail, Outlook for iOS and Android, etc.) don't use SMTP AUTH to send email messages.
Therefore, we highly recommend that you disable SMTP AUTH in your Exchange Online organization, and enable it only for the accounts (that is, mailboxes) that still require it.
There are two settings that can help you do this:
- An organization-wide setting to disable (or enable) SMTP AUTH.
- A per-mailbox setting that overrides the tenant-wide setting.
Is an error message displayed when sending the mails?
If necessary, activate the checkbox for displaying the dialogue box, which will also give you more information: