Re: Android 11: App polling interval is not 15 minutes minimum?

Frank Slootweg <this@ddress.is.invalid> wrote:

VanguardLH <V@nguard.lh> wrote:

I've been reading some web forums on e-mail clients, like for K9 on
Android where users complain they were forced to 15-minute minimum mail
poll intervals.  Some users don't have IMAP servers that support PUSH,
so they rely on very short poll intervals to react on e-mails within a
very short time they remain viable (e.g., 2FA codes that expire, job
contracts sent to a list of freelancers where the first to respond gets
the job).  The users thought a new version of K9 had implemented a
change to 15 minutes between mail polls from the prior version that
allowed down to 1-minute polls.  The conclusion was that Android 11 had
a restriction that apps were not allowed to poll servers at less than 15
minute intervals.
 
When I check IMAP PUSH, it only works in clients on the Inbox folder.
If the server moved a new message into the Junk folder, PUSH isn't used
on that folder for the client to see a new message show up there.  I can
get 2FA codes via e-mail that end up in the Junk folder, and those codes
expire, and often far shorter than 15 minutes.  I cannot whitelist the
2FA codes, because the sender is unknown to let me add them to a
server-side rule trying to keep them out of the Junk folder.  Just
because I'm trying to log into a site that issues a 2FA code doesn't
mean that is the host name that sends the code.  Besides, user-defined
rules are exercised AFTER the server has already applied its spam
filtering, so user-defined rules are ran too late.  The false positive
has already been moved into Junk, so it isn't in the Inbox folder when
the rules get ran.  One of my e-mail accounts has a Safe Senders
whitelist which overrides the server's spam filtering, but other
accounts have no such whitelist that is effected before the server's
spam filtering.
 
Does Android 11 have a limit (which seems unpublished) that IMAP apps
cannot poll at shorter than 15-minute intervals?  That would suck.

 
  From this (your OP) and following posts, it seems your main concern is
your e-mails with '2FA' (read: 2SV) codes ending up in your (IMAP) Spam
folder without you being notified.
 
  Can't you just manually 'poll' your Spam folder after you've entered
your login credentials at the website? Or doesn't the Android mail
client you're using have such a manual-poll facility?

The only time I use the webmail client is to define server-side rules,
not for checking for e-mails.

My Android e-mail client (MS Outlook) uses IMAP PUSH.  If it also polls,
it doesn't let me specify the interval.  I don't see it offers a manual
poll option.  I don't use the Gmail app; however, it makes you select
between IMAP PUSH, or a poll interval, not both.  I didn't see a manual
poll instigate in the Gmail app.

Since the IMAP PUSH/IDLE connections can be dropped by the server after
29 minutes, IMAP clients should, at least, poll every 29 minutes, or
shorter, to establish new connections.  K9 will poll at 24 minute
intervals unless you set to a shorter interval, but now 15 minutes is
the minimum in K9 claiming Android 11 (and maybe 10) won't let apps poll
at shorter intervals in the name of battery power saving.

  FWIW, I hardly use e-mail on my phone, but I have the BlueMail and
K-9 Mail apps and both can manually poll my Spam folder.

Yep, because IMAP IDLE only works on the Inbox folder.  The other
folders get updated via polls.

While many freebie e-mail providers don't have Safe Sender whitelists to
precede server-side spam filtering, and some won't even let you disable
server-side spam filtering, there's no way to override the false
positives ending up in the Junk folder.  Hotmail/Outlook.com does have a
Safe Sender whitelist that is supposed to supercede the spam filters.  I
have used it to prevent aliased e-mails (from AnonAddy) from getting
moved into the Junk folder by Microsoft's server-side spam filtering.
However, not all 2FA codes come from the same domain where you were
trying to login.  Too many sites contract that out.

2FA codes sent by SMS only show a phone number of the sender.  Although
I have Google Voice send a copy of SMS texts to my Hotmail address, I
don't see how I can define filters on them.  There are no e-mail headers
on which to test in SMS texts.