Aside from the fact that recruits generally won't have mail call every day, the timing is a bit screwy when sending mail to Basic. It often took odd amounts of time for my husband's letters to reach me and for mine to reach him. Sometimes he wouldn't get any for a week and then get three at once, even though they'd had mail call regularly. It just takes a little more time to get through the system than regular mail. Don't worry about it.
And just a tip, but you should number or date the outside of the envelope so that he knows which letter to read first and ask him to do the same.
And just a tip, but you should number or date the outside of the envelope so that he knows which letter to read first and ask him to do the same.