Distribution list problems

I created and successfully used a distribution list for my board members last week. Today, I tried to compose an email to the list, and only one address appeared for that list when I sent it (I checked in sent folder). However, when I went to the Contacts folder & looked at the distribution list, all addresses were there. So the list remained intact, but using it in the recipient field didn’t actually send it to everyone. For now, I just renamed the list & tried again, and now all the recipients are back when I try to populate the field… but I see from other questions that distribution lists have had issues in the past. Is there something I can do to fix this? Thanks

HI Sarah,
what email account does this happen on?