How to ask two questions?

If I send company accounts, tax return and tax computations in an email asking for the clients OK and a personal tax return and tax computations in another email asking for the OK, If I am in luck I usually get one of the emails answered. Clients seem incapable of answering more than one email.

If I ask a client if the attached company information is correct AND ask them for the SIC code(s) in the same email I usually get an answer to one of the questions but not both.

Am I overestimating client's intelligence? Should I include more than simple questions? I was thinking I could put a form in with a yes/no option and a box for the code. Should I colour the questions to make them more noticeable?

Should I give up on trying to get evidence of a clients response and phone them and ask them the questions? I could always record the conversations!

It's not even 9 am yet!