Why did Zoho Mail block outgoing mail for suspicious login activity?

Zoho Mail blocks outgoing mail when it sees signs that an account may be compromised, such as logins from unusual places, a sudden spike in messages or many bounces. It is protecting your domain and its servers from spam. To restore sending, secure the account by changing the password and turning on two-factor authentication, check for unknown sessions and forwarding rules, then follow the unblock steps or contact Zoho support.

Email providers watch for compromised accounts because one hijacked mailbox can send thousands of spam messages and damage everyone's sender reputation. Logins from a new country, many failed attempts, or a large batch of outgoing mail to unknown recipients can trigger a block. Sometimes it is a real attack, and sometimes a legitimate bulk send or travel looks suspicious.

First, assume the account may be at risk. Change the password, turn on two-factor authentication, and review active sessions and connected apps, ending any you do not recognise. Check for mail forwarding rules or filters you did not create, which attackers often add. If you use IMAP or SMTP in other apps, use app-specific passwords.

Then request the unblock. Admins can see blocked users in the admin console, and Zoho may ask for confirmation that the account is secure. Do not send bulk marketing from Zoho Mail. Use Zoho Campaigns or ZeptoMail for that, which are built for volume.

Written by Flowpeak, a Zoho implementation partner. Zoho pricing and features change, so confirm current details on the official Zoho site. Free checklists | Ask us a question