Mobile devices can't connect to exchange server

mitchel1998 Posts: 2  Freshman Member
edited April 2021 in Security

I have recently installed a Zywall-110 in our network to improve security of our company network.
Before this we didn't have a proper firewall and only a modem from our isp. After having configured everything and installed the zywall110 in the network everything worked fine. Except that the mobile devices can no longer connect to the exchange server through internet.

I have read that this may have to do with the https request time out setting. Unfortunately, I can not find any settings in the zyall110 here.

Can you help me with this problem because I do not know where to look anymore.

thanks in advanced,


  • Zyxel_Charlie
    Zyxel_Charlie Posts: 1,034  Zyxel Employee
    Hello mitchel1998,
    If the exchange server is behind device, you should create Nat and security policy to allow traffic from wan to server. Please follow the below steps.
    Group the services fro mail server

    Create the Address object for Server

    Add the security policy and Nat profile

    Since exchange Server occupy  the port 443 which is the same with our device managed port, you need to change the device managed port to another. 

    Note: You should type IP address with port 55555 to login device next time.

  • mitchel1998
    mitchel1998 Posts: 2  Freshman Member
    Hello Charlie,

    I've done what you have showed me but it didn't make a change to the situation...
    Do you know maybe something that is blocking? or is there maybe another solution?

  • Zyxel_Charlie
    Zyxel_Charlie Posts: 1,034  Zyxel Employee
    Hello mitchel1998,
    To analyze this case, please check as below.
    1. What protocols does your mobile configure(SMTP/POP3  or Exchange mode)?
    2. Which mail server does your mobile connect with? ( or
    3. we need you collect packet on Wan and Lan interface, when your mobile try to connect with Server.

  • Daniel_LU
    Daniel_LU Posts: 16  Freshman Member
    edited February 2018
    do you have ssl inspection or content filtering active?

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