Three Mail-Accounts in AquaMail Pro 1.5.7.18

[Dworf]

Hello!
I have three Mail-Accounts in AquaMail Pro 1.5.7.18.
(Android 5.0.2, Kernel 3.4.42-gdd242b0, 22.1.2015)
One deletes the Mails after checking the messages from the server, the other
two keeps them. I have checked in all three accounts "In AquaMail ausblenden, auf Server behalten"
and "Nachrichten werden beim nächsten Login vom Server gelöscht".
What is the mistake I make?
Thank you!

[Dworf]

The two account which keeps the messages: t-online.de & yahoo.de
The one where the mails have been deleted: gmail.com
Thunderbird 2.0.0.24 is accessing the accounts via desktop-pc
All 3 accounts are configured as POP3 identically (I believe & hope)

[Dworf]

Thank you, I'tried the Recent-Mode, but it
doesn't worked out. I've been taken a look
via Firefox on the Webmail-Interface and all
the mails are still there and haven't been really
deleted. Marked as unread.
But Thunderbird can't see them anymore.
T-online and Yahoo seems to handle something
different. Maybe no AquaMail-Problem?
I will test the IMAP-Mode.
Thank you again for your support!

[Dworf]

So what happens is this:
AquaMail seeks for new Mails at GMail and finds
one new and loads it onto the MobilePhone.
And the Mail is still visible for Thunderbird.
If I seek with AquaMail an hour later again,
the Mail isn't visible anymore for Thunderbird.
So at the second seek something happens.
But what?

[Dworf]

Well, you were right: IMAP solved the problem!
Thank you, Paris Geek!

[Dworf]

I've found an interesting Help-Issue in the Help-File
of the MagicMailMonitor from Valeriy Ovechkin:

"No RETR (gmail.com)
Use this option when working with GMail box.
GoogleMail server marks message as read after you download it with RETR command.
As result message disappear from the MMM's list.
This option forces MMM to use alternative reading method."

Is any similar option available in AquaMail Pro 1.5.7.18?