Hello Lyanne

Welcome to PCHF
If I understand correctly, you have 3 people that you can not send Excel attachments to? You can send .xls attachments to other people and they can open them just fine, just not the certain three people?
Can those three people receive any other type of attachments, just not .xls ones?
Can they open .xls attachments that other people send them?
Let me know and we can go from there.
