Deleted mails still show up in iOS (Active Sync)

Deleted mails still show up in iOS (Active Sync)

Hi!

When I delete mails or move them to a different folder in Thunderbird or Zoho-Webfrontend they still show up on the iPhone in the Inbox.

The iPhone uses Active Sync to connect with Zoho.

I already activated the Expunge and the "move to Trash" within Thunderbid and Zoho.