Users not able to sync email to mobile devices or mail clients anymore

Users not able to sync email to mobile devices or mail clients anymore. Sync hasn't worked since 8/16/2018. users CAN use webmail clients installed on the server such as roundcube still, but no external client is able to sync.



What error are users getting exactly?

they aren't getting any error, but devices and clients aren't syncing either. when using roundcube we can see that there are new emails that have come in, but not syncing to the client devices or email clients

When opening up one of the clients, you may want to check the logs in /var/log/mail.log to see if there are any errors that are showing up.

I don't see any errors showing up. there are some standard incorrect email login requests for addresses that aren't on the server (people trying to brute force), but nothing from accounts that are actually on the server when they try to connect/sync.

Hrm, that all sounds very unusual... RoundCube uses the same IMAP mechanism as other clients would use.

Do you perhaps have a different client you could temporarily setup to see if you're able to receive email that way?

And how many users are seeing this issue?

All users are seeing the issue, I don't have an extra domain I can test with to see if new users are affected. I have also noticed that once I send an email from the server, it becomes completly unresponsive via web interface, and ssh untill I forcably reset the VM. this VM is less then a month old.

Hrm, that's a really strange sounding issue.

Sending a single email shouldn't ever affect the web or SSH service, I don't know how it even could.

It sounds like something very unusual is going on there.

What is the output of these commands:

free -m
mailq | tail -1
dmesg | tail -30

Also try to remember if in the meantime working <> not working things have changed and what....

I did for example some manual changes when looping / or other to many connections..... because of failing thing like ;, and so on from whatever , for example firewall /spam configs but also PHP scripts , and de postfix dovecot configs...could cause strange behaviours.

Did roundcube worked before the synch and with synch working, updates roundcube / mariadb, user rights and so on

ofcourse as asked above all log and other file info's for the Virtualmin support Guys. ;) ( VERSIONS and so on wich OS.... )

This is my last comment this topic only mentioning writing above, so don't be afraid i 'm going offtopic here and so on. ;)

here is the output of free -m

root@websrv:/home/kstevens# free -m
              total        used        free      shared  buff/cache   available
Mem:           3955        2200         105         802        1649         719
Swap:          4093           0        4093

output of uptime is root@websrv:/home/kstevens# uptime 22:31:13 up 11:27, 1 user, load average: 0.15, 0.10, 0.06

mailq | tail -1

root@websrv:/home/kstevens# mailq | tail -1 Mail queue is empty

dmesg | tail -30

root@websrv:/home/kstevens# dmesg | tail -30
[    4.318658] [TTM] Zone  kernel: Available graphics memory: 2025424 kiB
[    4.318660] [TTM] Initializing pool allocator
[    4.318664] [TTM] Initializing DMA pool allocator
[    4.318752] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    4.318754] [drm] No driver support for vblank timestamp query.
[    4.318842] [drm] Screen Target Display device initialized
[    4.318901] [drm] width 640
[    4.318911] [drm] height 480
[    4.318920] [drm] bpp 32
[    4.319429] [drm] Fifo max 0x00040000 min 0x00001000 cap 0x0000077f
[    4.320477] [drm] Using command buffers with DMA pool.
[    4.324497] [drm] DX: no.
[    4.329156] fbcon: svgadrmfb (fb0) is primary device
[    4.329295] Console: switching to colour frame buffer device 100x37
[    4.336600] [drm] Initialized vmwgfx 2.12.0 20170221 for 0000:00:0f.0 on minor 0
[    4.336695] shpchp: Standard Hot Plug PCI Controller Driver version: 0.4
[    4.434404] sd 3:0:0:0: Attached scsi generic sg0 type 0
[    4.434448] sr 2:0:0:0: Attached scsi generic sg1 type 5
[    4.484940] input: PC Speaker as /devices/platform/pcspkr/input/input6
[    4.720050] Adding 4192252k swap on /dev/sda5.  Priority:-1 extents:1 across:4192252k FS
[    6.125842] EXT4-fs (sda6): mounted filesystem with ordered data mode. Opts: quota,grpquota,data=ordered,usrquota
[   10.761038] vmxnet3 0000:0b:00.0 ens192: intr type 3, mode 0, 3 vectors allocated
[   10.761798] vmxnet3 0000:0b:00.0 ens192: NIC Link is Up 10000 Mbps
[   11.145587] ip6_tables: (C) 2000-2006 Netfilter Core Team
[   11.367566] Ebtables v2.0 registered
[   11.532546] nf_conntrack version 0.5.0 (16384 buckets, 65536 max)
[   12.264847] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[   13.829958] Netfilter messages via NETLINK v0.30.
[   13.854695] ip_set: protocol 6
[   65.131453] TCP: ens192: Driver has suspect GRO implementation, TCP performance may be compromised.