Grammar in Use by Murphy (Cambridge Press) is an excellent book. It has two-page units (one page of explanation and examples and one page of exercises). Some editions have answers in the back. Grammar comments -Please send me... (This is an imperative "send me" softened by "please.") More information on imperatives: https://grammar.collinsdictionary.com/easy-learning/the-imperative - I'll send you a message when I get home. (structurally the same as a type 1 conditional with "when" replacing "if" - If/When I get home, I will send you a message.) More information on conditionals: https://grammar.collinsdictionary.com/easy-learning/conditional-clauses The simple present can be used for a certain future event, mostly involving transportation. - My plane leaves for Paris on January 2 at 10:30 AM. The simple present continous can be used for a certain future event, mostly involving people. - I am leaving for Paris on January 2 at 10:30 AM. Grammar in Use Intermediate has four units on the simple present, the periphrastic formula "going to," and the simple future for future events.

I believe that they are grammatically correct but I am not sure. They all sound correct though. I wouldnt have a problem saying any of these. In fact I think I have said several of them before. I would say yes, they are fine.

'when I'm done' is a time expression (in the future), it's not a future sentence. 'I'll send it to you' is a future sentence, but one that is a promise or just decided. 'will' isn't used if you have decided it before; 'I'm going to send it' or arranged it with someone; 'Im sending it with something' :)

@Keith, :) A programmer's habit to use "clever" words :)

"Is it ok to use ..?" :)