Iphone 5 emails disappearing

[kylo67]

My Iphone 5 emails are disappearing. My yahoo email account is ok, but the Comcast email account disappears. I deleted the comcast account and reinstalled it twice to no avail. They still disappear. My Comcast account on my computer is fine. Just the phone has them disappear. My "incoming mail server host name" on my iphone 5 is different from what was on my iphone 4s. The iphone 5 host name is......imap.comcast.net and the iphone 4s host name is......mail.comcast.net. I never had issues with the iphone 4s mail. Any thoughts. Thanks