This app was mentioned in 4 comments, with an average of 1.00 upvote
Check out MailCal . I've used it the past couple of years without any problems. Also the developer is very responsive to questions.
I'd recommend MailCal (Link: https://play.google.com/store/apps/details?id=com.devsite.mailcal) . It is clean, does both email and calendars, and provide reasonable settings. Our company has BYOD policy but requires giving Admin privileges to company servers. I didn't want to do that, and found MailCal to do the job over webmail satisfactorily.