SMTP Issue

[K@yT]

Hi Net-Worriers 

Here is a network nightmare i am confronting, clients have internet access on the PC but Ms Outlook can't send/receive emails on LAN but everything works fine on WiFi. DNS, SMTP or Service Provider issue? 

[Seb Rupik]

Hi there,

The Layer3 interface which provides the gateway for the VLAN, does it have an ACL on configured on it? Likewise the Layer3 interface connected to the MS Exchange VLAN?....or pretty much any Layer3 interface in between. Possibly either the LAN subnet is being blocked from reaching Exchange or maybe just TCP/25 ?

cheers,

Seb.

[Richard Burts]

We do not know much about this environment. There are several ways to look at the issue described and it is difficult to know which is more appropriate. So any additional information you could provide would be helpful.

My first thought was that if email does not work on LAN and everything is fine on wifi that it is hard to see this as an issue with SP. And then I thought "how many email servers are they likely to have?" and the associated thought "perhaps there is not any email server on wifi, so everything on wifi works, but it still could be an issue with SP.

If there was a problem with incoming email but outgoing email worked then I might suspect a problem with static nat for the email server. But if the problem is both incoming and outgoing it is probably something else.

And then I realized that I have been assuming that the email server is inside the network. But as I read again the original post it only says MS Outlook can't send or receive. So we do not know if the mail server is inside the network or outside somewhere. That would make a big difference.

So please tell us more about this network.

[paul driver]

Hello

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K@yT wrote:

but everything works fine on WiFi. DNS, SMTP or Service Provider issue? 

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is this office 365 email or are your email servers local?

Is the wifi subnet internal if so then it must be ran off a rtr/l3 switch where your wired subnet should also  be

Are your wired lan users using the correct  dns servers as your wifi clients?

When you are setting up outlook for these wired clients do you have to manually append the email server name if so have you tried using ip address instead?

[K@yT]

Hi @paul driver Yes, (Local) and but our exchange is not online,hosted externally..

Yes, the Dns servers are correct.

When i setting up outlook for the wired clients i don't have to manually append the email server name it automatically detect it.

 

[paul driver]

Hello

Do wifi and wired users connect with different devices or can the same device work on wifi but not on wired if so then i would t say isn’t  a client issue 

i would suggest you check the device that is performing the routing for your lan clients 

if your wifi users have no issue but wired clients do then it sounds like it’s a permission issue negating the wired subnet.

[K@yT · Accepted solution]

[Solution]: We had to run network performance assessment from Microsoft team to clean up o365 exchange data after i assigned new IP address range. 

Boom everything was working fine.

Just left with network congestion. 

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