email client that is able to handle calendar invites with multiple email/calendar accounts

Occasional Contributor

Hello all,

I am posting this discussion because i am amazed at the fact that I cannot find an email client that is able to appropriately handle calendar invitations to/from myself for multiple email addresses and associated calendars.

With Outlook, my issue is that Outlook views my Exchange account as the default calendar account, so that when I accept an appointment to any other non-Exchange account (eg IMAP), the person who sent the invitation gets an 'accept' email from my exchange email address, and not from the email address to which he/she sent the invitation. This looks very unprofessional.

Thunderbird works better and allows for calendars to be matched to email addresses, but has a bug with accepting calendar invites that still has not been resolved:


Is anyone aware of an email client for Windows that is able to appropriately handle multiple email accounts (exchange, imap, etc) and associated calendars (exchange, caldav, etc)?



10 Replies
best response confirmed by rik1234 (Occasional Contributor)
Remove the Exchange account - set the IMAP data file as default and restart Outlook. This creates a calendar in the IMAP data file. Add the Exchange account back.

Accepting the event should send it from the correct address now - but it will be on a separate calendar. Normally this is not a big problem since you can overlay calendars, but if you need them on one calendar, you would need to move or copy the event.

thanks for the help and your reply. Indeed, what I want is a separate calendar for each account, so that calendar accepts come from the right email address, and so that i can overlay them in the calendar view. I then would like to use CalDav synchronizer to sync all the IMAP calendars to their web versions so they are backed up.

I have 5 IMAP accounts, besides the exchange account, so i followed your advice for each IMAP account after removing the Exchange account: set it as default --> restart Outlook --> set the next IMAP account as default --> restart Outlook, etc. Then at the end i added back in the Exchange account. This has worked partially. One of my IMAP accounts now has a separate local calendar that is linked to the IMAP email account. Calendar accepts are sent from that account instead of the Exchange account. However, for all the other IMAP accounts, there are no local calendars, and calendar accepts still come from the Exchange account. Strangely, the 1 IMAP account for which there is now a local calendar is not the one i set to default last before adding back in the Exchange account (but second-last).

Any advice for how to create a local calendar for each of my 5 IMAP accounts, so that i can accept calendar invites from all of them from the right email address?

to anyone with this same problem, i found a workaround for accepting invites:
To press "edit the response before accepting" in the calendar invite. When i do this, I am able to change the sender from my Exchange account to the correct IMAP account, and then the invite comes from the correct address. You can then keep all your calendar appointments in the default calendar, or you can drag them manually in the calendar overview to other local calendars, as you wish.


Unfortunately, this only solves 1 part of the problem. The other part is that when initiating a meeting myself, when i do that from another email address than the default exchange one, it sends the email from the default exchange email accounts (and adds "via <the correct account>". Again, this looks really unprofessional. The only way to solve it seems to be to create a local calendar for each IMAP email address like @Diane Poremsky suggested, but i have not been able to succeed so far in doing so except for 1 IMAP account, out of 5. 


ah i found the solution myself. I only set the default Email account to the IMAP accounts, but what you need to do is set (also?) the default Data File account to the IMAP accounts. Then a calendar gets created per IMAP account.
Thanks so much for the help, this is solved now!!

alright so I'm posting here a guide for how to get this all working in Outlook, in case anyone else needs it:


  1. Set up a different calendar for each email account, by deleting all Exchange accounts (restart Outlook) + then set each IMAP account to be the default email account + also the default data account (that’s the next tab in accounts, that’s important because otherwise it does not work). Restart outlook after doing so for each outlook account. After doing this for each account, re-add the Exchange account(s) back in.
  2. Then connect IMAP calendars with rhe CalDavsynchronizer plugin for Outlook. In Cpanel, you can find the setup settings by going to “manage” for an email address.
  3. If you want to check if the appointments are being synced: the calendars are only visible if you use the Horde email client, not if you use Roundcube.
  4. After setting up a different calendar for each IMAP account, you can accept meeting requests directly in the email. The reply email address will now be the correct one.
  5. Setting up a meeting appointment yourself has to be done by:
    1. From the email tab in Outlook, and then “new”, and then meeting
    2. From an email from someone, and then hit the 3 horizontal dots at the top right of the email, and then ‘meeting’
    3. Or by selecting the specific calendar you want in the calendar tab, then making a new appointment there. If you don’t do that first, and just click ‘new meeting’ in the Calendar tab without first selecting the right calendar, the meeting will be sent from the default exchange account, even when you select a different email address as the sender.
@rik1234 thanks very much for the detailed walkthrough, you saved me a lot of headache!
My pleasure. I actually just moved to Linux and can say with confidence that using email with multiple accounts is much easier there (i'm using the Evolution app, bc Thunderbird once gave me issues with accepting calendar requests on windows). In Evolution, I only have to have 1 calendar, and when I accept meeting requests on any email address, the reply to the meeting organizer is from that email address, while the appointment goes in my calendar account belonging to a different email address. Much easier, and makes the 'Outlook way' of using a different calendar for each email account unneccessary.
Mate, what a thread?! I have the exact same situation that you described in your opening description. I am keen to try the steps you listed above (I realise you have now moved on to a Linux based solution but I don’t think I am game to try that path just yet), however my IMAP email is hosted on siteground (no cPanel), which I believe means I can’t use the caldavsynchronizer plugin. Would that be correct?

@IndyChabbra hmmmm i don't know, is there some other way to identify the relevant settings for your Siteground email? You could always email them to ask, i'm sure they can look it up

@rik1234 thanks for the steer, I shall ask them. Will drop a line here when I find out more.