[SOLVED] timeout after DATA

felix_84

Member
Oct 22, 2017
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Hi everyone, just installed and configured PMG 6.0, everything works good, except some clients can't connect to SMTP.
in mail.log i see only this kind of messages:

connect from client [ip]
timeout after DATA (0 bytes) from client [ip]
disconnect from client [ip] ehlo=1 mail=1 rcpt=1 data=0/1 commands=3/4


OR

timeout after DATA (591 bytes) from client [ip]

OR

lost connection after BDAT (1157 bytes) from client [ip]

What i tried:
-whitelist ip in fail2ban
-disable fail2ban completely
-whitelist ip in postscreen
-whitelist from SMTP checks in GUI

graylisting permanently turned off

On router i see the connect session to 25 port hanging untill timeout

I also tried to capture packets from particular client, but for me its non informative

SMTP 91 0.000087000 S: 354 End data with <CR><LF>.<CR><LF>
TCP 91 0.210234000 [TCP Retransmission] 25 → 56729 [PSH, ACK] Seq=262 Ack=179 Win=64256 Len=37
TCP 66 0.006393000 [TCP Previous segment not captured] 56729 → 25 [ACK] Seq=13979 Ack=299 Win=5760 Len=0 SLE=262 SRE=299
SMTP 12 299.881855000 S: 421 4.4.2 Proxmox-smtp Error: timeout exceeded


Google points to network misconfigurations like wrong mtu on host,vm,router etc...but first of all, we have more than 500 emails per day, from hundreds clients and only this particular experienced such troubles. But this is huge organisations like banks, so i don't believe that there can be such misconfigs too...

Thanks in advance for you suggestions!


pmgversion -V
proxmox-mailgateway: 6.0-1 (API: 6.0-6/b0c1ded4, running kernel: 5.0.21-2-pve)
pmg-api: 6.0-6
pmg-gui: 2.0-4
pve-kernel-5.0: 6.0-8
pve-kernel-helper: 6.0-8
pve-kernel-5.0.21-2-pve: 5.0.21-3
pve-kernel-5.0.21-1-pve: 5.0.21-1
libarchive-perl: 3.3.3-1
libjs-extjs: 6.0.1-10
libjs-framework7: 4.4.7-1
libpve-apiclient-perl: 3.0-2
libpve-common-perl: 6.0-4
libpve-http-server-perl: 3.0-2
libxdgmime-perl: 0.01-5
lvm2: 2.03.02-3
pmg-docs: 6.0-3
proxmox-mini-journalreader: 1.1-1
proxmox-spamassassin: 3.4.2-12
proxmox-widget-toolkit: 2.0-7
pve-firmware: 3.0-2
pve-xtermjs: 3.13.2-1
zfsutils-linux: 0.8.1-pve2
 
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Similar issue here, would be good to know what resolved this? Thx,.
PMG is behind NAT -> public proxmox host IP vmbr0 with MTU 1500, and private PMG IP vmbr1 with MTU 1450.

Seems to be expected: https://pve.proxmox.com/pve-docs/chapter-pvesdn.html#pvesdn_setup_example_vxlan
VXLAN zone configuration options:
Peers Address List
A list of IP addresses of each node in the VXLAN zone. This can be external nodes reachable at this IP address. All nodes in the cluster need to be mentioned here.

MTU
Because VXLAN encapsulation uses 50 bytes, the MTU needs to be 50 bytes lower than the outgoing physical interface.
 
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