IMAP sync issue with Sent folder

IMAP sync issue with Sent folder


I'm using Thunderbird 12.0.1 and IMAP folder syncing has always worked well, until recently when the
Sent box would sporadically sync-- sometimes immediately, other times it would take hours to half a
day. Even when I right-click the folder to force "Download Now", it does not work.  or would need Folder repairs doesn't always work.

The other folders work fine (Inbox, Inbox subfolders, Trash, etc) only the Sent folder is
affected. However, on my iPhone, it syncs immediately, so it's a Thunderbird-Zoho issue
specifically, I suppose.

Kindly advise how to correct this.

I did a tracert which got stuck on 74.201.154.17 from hop17 to end hop30.