The following describes the correct settings for Outlook 2016 for your IMAP server.

When firstly adding the account.

Account Type: IMAP

Incoming mail server:

Outgoing mail server (SMTP):

User Name: Full email address.

Ensure that “Require logon using Secure Password Authentication (SPA)” is unchecked.  We have a secure mechanism in place but we do not use SPA.

Next, click into “More Settings”.

Incoming server (IMAP): 143.

Use the following type of encrypted connection: STARTTLS
Or, if STARTTLS is not listed, TLS

Outgoing server (SMTP): 587

Use the following type of encrypted connection: STARTTLS
Or, if STARTTLS is not listed, TLS

Server timeouts: 1 minute.

If you are on your own server:
Root folder path: make sure it’s empty

If you are on our shared email server:
Root folder path: INBOX (All caps)

Do not save copies of sent messages: unchecked/disabled.

Purge items when switching folders while online: checkbox/enabled.

Subscribing or Unsubscribing to IMAP Folders (Optional)

You might like to choose which folders show up in Outlook.

Outlook 2016 and Spam

Spam will regularly be detected and automatically filtered by the email server into the ‘Junk’ folder.  Any spam you receive in your Inbox should be moved into the ‘Junk’ folder manually.  This is important.  Deleting spam, rather than moving spam into the ‘Junk’ folder, can potentially disrupt the server’s automatic spam filter.

We recommend disabling Outlook 2016’s spam filtering, if possible.  It’s spam filtering interferes with the email server’s learning capabilities.    Unfortunately we cannot direct Outlook to move spam into the proper folder automatically without some hacks with potentially negative side effects.  Instructions for how to disable Outlook’s spam filters; we recommend selecting ‘No Automatic Filtering’.

Setting the Sent Items Folder

Please see this discussion if Sent Items are not saving properly.  Let us know if this is something you would like assistance with.

Kaspersky Virus Scanner

There is a setting change recommended when using Outlook with IMAP.  This is to disable port scanning; apparently, scanning traffic as it travels through the ports causes an IMAP synchronization issue.  Email scans are still performed.  We recommend disabling “Anti-Spam” and also in Email Advanced Settings, to uncheck “Scan POP3, SMTP, NNTP, and IMAP traffic”.

Troubleshooting IMAP Automated Syncing in Outlook:

There is sometimes problems with automated syncing and connectivity.  The following links may shed some light on how to fix this.

Send/Receive groups should be looked at.  In particular, we should ensure that ‘Schedule and automatic send & receive’ is set for every 1 minute.  It is also possible that we need to copy the default Send/Receive group, setup the copied group, then delete the default group.

The following links also discuss possible fixes to a slow Outlook applications.