GroupJive Invite email notification

I am testing the GJ invite notification, the system is set to GJ > configuration>notifications>global>Notify By PMS & Email. When I send invitation to some users, certain user gets email notification and some don't. It seems everyone gets PMS though. I tested few times, got the same results.
Is there other settings I should look into?
Thanks.

It's likely they're getting the email, but it is being sent to their spam folder. There's nothing in the code to discriminate against a specific users email address. Issue is likely either on the sending mail server or receiving mail server. Contact your host and see if they can check outbound mail logs to see if one of the email addresses of the users that didn't receive an email was event attempted to be sent the email.

Right, the emails were sent, some were in junk folders and some must got kickbacked.
With further tests, I found that it happens when I override the "From Address" at notification setting. All emails go through when I leave this box empty, then the emails go out with sender's email address. My problem is that I would not show the user's personal email address on the invite notifications. Can it be simply like the connection request notification?

Ensure you provide a valid and working From Name and From Address. Aside from that it still sounds like it's the recipients mail server rejecting the mail instead of your mail server not sending it. Why it's being rejected is likely due to spam protection. When it's sent with the users email address it looks less like spam. When 100+ emails for example are sent with same from name and address in a similar time frame it looks like spam. Not much you can do about this except contact the mail servers rejecting your emails and ensure they know you're not spam.

Thank you!
It still really puzzles me though that other notifications like member join, wall post, etc, seem to go through without any problems while the invite notifications get blocked. They have the same name and email address from the same configuration setting.

It depends entirely on the from name, from address, subject, body of the message, or if your domain/ip has been blacklisted. Try changing the invite subject and body language strings to be a little bit more unique.

If you're going to be sending regular mass email you really need to contact mail servers and make sure you aren't going to be blacklisted, because all it takes is a few people clicking the Spam button and you're done for. Getting off a blacklist is near impossible for some mail servers. This is less likely to happen when the mail server thinks the email was sent from a legit person, which is why that's the default, but yes it does expose the users email address.

Eventually we'll have an on-site notification system (kind of like Facebooks notification globe) so that mass emailing really won't be the norm anymore.