Email send to distribution list is received as spam to the External receipent but internal receipent of the same domain receives in INBOX

Question

Environment

*10 Active Users -users inside the tenant

*20 users are in Contacts - Users including gmail,hotmail and the users from external domain

*Created a distribution list named "Communication Group" with address "communication@.....com" where both domain users and the users that are available in the contacts are added.

For Example

I have a distribution group with address " it @ contoso com "

where the internal domain members are
user1 @ contoso com , user2 @ contoso com , user3 @ contoso com user4 @ contoso com

Also, in the same group external members are also added example

user1 @ hotmail com , user2 @ yahoo com , user3 @ gmail com , user 4 @ msn com etc

The distribution group contains both internal domain users and external domain users

Issue

• When an email is sent to the distribution group, the domain users receives the email in the INBOX FOLDER whereas the contacts users (outside domain users) of the same distribution group receives the email as spam and received in Junk folder.

**External recipients receive email messages that are sent to a distribution group in junk folder

Solution ?

Answer 1

I actually have a problem like this. When I receive an important message, sometimes I find Outlook classifies it as junk mail or an unsupported message and gives me a notification that this message is checked, of course from a trusted mail such as Flip Grid or even Microsoft itself, and it always blocks the contents of some messages until I ask it to show full message
How can I solve this problem?

Answer 2

If this is happening when sent from internal users, then I would say you need to check your SPF record first and ensure its set correctly and includes your sending IPs

Answer 3

In tried in my lab environment also,

i have only .onmicrosoft.com domain there also when any of the user for example "abc @ 123 .onmicrosoft.com" sends the email to distribution list the internal domain users receiving in INBOX but the emails like ".. @ hotmail.com" ".... @ yahoo.com " etc which are the member of same distribution group receiving the email in JUNK

How can I check the SPF record of .onmicrosoft domain ?

Answer 4

@Andy David - MVP

Answer 5

You can check here:

https://mxtoolbox.com/spf.aspx

Since this is the onmicrosoft.com domain, it should already have a SPF record.

In which case, it could be two reasons messages go to junk.

1. Its a new domain and the major ISPs do not yet trust it.
2. You are sending "spammy" messages

In either cases, there isnt much you can do except ask the recipients in those domains to add to their safe senders list.