Update Update-DistributionGroupMember.md

Issue #7787

Author: chrisda

exchange/exchange-ps/exchange/Update-DistributionGroupMember.md

@@ -139,6 +139,8 @@ You can enter multiple values separated by commas. If the values contain spaces
 
 Although it isn't required, it's a good idea to add only security principals (for example, mailboxes and mail users with user accounts or other mail-enabled security groups) to mail-enabled security groups. If you assign permissions to a mail-enabled security group, any members that aren't security principals (for example, mail contacts or distribution groups) won't have the permissions assigned.
 
+The maximum number of entries for this parameter is 10000.
+
 ```yaml
 Type: MultiValuedProperty
 Parameter Sets: (All)