It is very common for researchers to share published articles upon individual requests, and many copyright transfer statements explicitly allow this.
In the case that the copyright transfer statement does not explicitly allow sharing the published article in any form, is it allowed to share a published article upon request? So suppose that the copyright statement is completely mute on the topic, it simply transfers all copyright aspects to the publisher, except for intellectual property etc. In that case, as the author of the article, is it even forbidden to mail a version to a fellow researcher, or a co-author of the article?
Does this also hold for the pre-print version? For an early draft?