NethServer, no matter if you’re using SoGo, WebTop or whatever supports synching all mail with IMAP/IMAPs. Outlook is “usable” with IMAP, it works stable.
I have a client who has about 120’000 mails in Outlook on NethServer, using IMAP…
Add to this that that client always has about 100 mails in edit mode, about 100 Word documents open, and in Firefox 100+ active tabs, I’m quite surprised how well it works…
honestly I got no problem with Imap and 30 client sending and receiving, I was fascinated by the feature of auto sync company addresses and looking for shared calendar option (something with free/busy there) … with all this remote working, I’m looking for a way to let have a global vision of all meetings running…
IMVHO IMAP sync only emails, not other informations (Calendar, Address book) between dovecot (NethServer) and Exchange. Dovecot no-groupware, WebTop is.
For Webtop there’s also the component EAS (Exchange Active Sync) which is design to communicate from Webtop to devices (phones, tablets, Outlook 2013) and back, not for syncing with Microsoft Exchange (AFAIK).
If you wish, you can dump data on PST and import data from Outlook 2013 (or later) to Webtop but… Never had a run before…
I have a valid ssl certificate installed on Nethserver and connection are finely secured, but after a double check I think webtop refers o an old certificate not longer installed, no longer valid, how can I check this incongruence?
If you want to use EAS on Outlook you have to create 2 accounts: one for mail with imap/smtp connection and another one with EAS connection for calendars and address books (which also synchronizes your mail and you can’t exclude it).
This leads to an unspeakable confusion on Outlook because you have two separate accounts and you get crazy to manage them.
If you want to use Caldav and Carddav with outlook you have to install this component on outlook: