Sending, receiving, and organizing email in Outlook on the web for business
For reasons that baffle me, the brain surgeons at Outlook have made it a separate button instead of leaving it as a standard feature. I guess someone was bored one day and decided to mess about with the set up to look like they were working.
Anyway, it's on the right hand side of the panel, so now you have to perform a pointless extra click to do what should be a straightforward act.