Sometimes an email inbox may get corrupted, which causes some emails to not be viewable in Webmail. Rebuilding uidlist or Repairing the mailbox will repair this problem. This article describes how to repair a broken mailbox in the event all emails are not displayed.
Utilize the "doveadm" utilize to force resync the inbox.
doveadm force-resync -u firstname.lastname@example.org INBOX
Note: Be sure to replace "email@example.com" with the broken mailbox user.