Error sending mail when trying to request a wiki account

[Hālian]

When trying to request an account on the wiki, I get the following error message:

Error sending mail:

Failed to send data [SMTP: Invalid response code received from server (code: 550, response: 5.4.6 Unusual sending activity detected. Learn more. Use the link mail.zoho.com/UnblockMe to unblock)]

This persists no matter what email account I use, be it Outlook, Zoho, or one from my own website. Please advise.

[Raion]

I'll look into it. Please standby, I won't be able to look more into this until this evening.

[Raion]

This appears to be fixed.