Many large buildings in the past had mail chutes[1]. I’ve worked in a building with one; it also had a pigeon-hole messagebox per floor so people could get their mail.
It wasn’t used that much, though, except for the odd journal subscription that someone had delivered to their office address. The system would only work with envelopes and magazines, anything bigger had to be collected from a central mailroom.
Sending mail between offices was a little more convoluted —you could just use the post or a courier yourself, but if you got your document or memo in the hands of the right person (typically a mailroom clerk) before a cut-off time, it’d be sent as part of the company’s larger delivery.
It wasn’t used that much, though, except for the odd journal subscription that someone had delivered to their office address. The system would only work with envelopes and magazines, anything bigger had to be collected from a central mailroom.
Sending mail between offices was a little more convoluted —you could just use the post or a courier yourself, but if you got your document or memo in the hands of the right person (typically a mailroom clerk) before a cut-off time, it’d be sent as part of the company’s larger delivery.
[1] https://en.wikipedia.org/wiki/Mail_chute
PS. Google Image Search has a good selection of office memos.