Inbox syncing with iphone vs. Android

I've recently switched to an iPhone 6 from a Samsung Android phone. With the Samsung, and with my android tablets, if I delete a message on Webmail or download all my messages to outlook on my computer, the older phone and the tablets would reflect these changes - that is, the mails would be deleted. With the iPhone, the mail never gets deleted unless I manually delete it there. I've read about POP3 not supporting this capability in general, yet it works on 2 android tablets I currently have, and my older Samsung phone, all of which are running POP3 with the exact same settings as my iPhone. Why is this? Is there a workaround? I can't believe Apple has sold so many devices and VZ is one of the leading ISP's in the US, and this issue exists? Tech support for Apple is giving me mixed messages - this is the way it's supposed to work or no, something's wrong but we don't know what it is - and both Apple and VZ are somewhat saying it's the other's problem.