Allow emails to multiple recipients using the CC field
It is great to have a mail merge feature built into insightly but sometimes you need to be transparent about who else received the email (if only to allow recipients to reply-to-all). Currently, I see no way of using insightly for this (except for manually entering the recipient emails into the CC field, and when doing so, there is not even an autocomplete function to help you do the job. You have to completely type in every single email-address. So it's just a no-go.)
So may I suggest the following quick-fix for this: based on the list of contacts displayed on the right when creating an email in insightly, create a mailto-link that is displayed above that list (or wherever, see screenshot), saying something like "send externally" or "send as ordinary email" or "copy email addresses to external program".
Clicking that link would open your email program (or in gmail if the user has that activated in the settings) with all of the listed email-addresses in the TO field (and perhaps the users own insightly address in the bcc).
Alternatively, there could be a tick-box saying "do not use mail-merge" or something like that which would toggle the mode of sending inside insightly but I guess that would need a lot more work and would also be more error-prone/ support intensive.
So how about that mailto-link?