I did some research on that. This server is on Microsoft azure and their virtual networks do have a firewall built in which inspects inbound packets. There isn't a firewall on the VM itself. What type of setting should I be looking for in the firewall? On Thu, Sep 22, 2016 at 2:08 AM Harald Paulsen <har...@paulsen.no> wrote:
> is there an old cisco pix firewall, or any other firewall with packet > inspection involved? > > > Harald > > Sent from my iPad > > > On 22. sep. 2016, at 06.24, Joseph Thibeault <j...@dashride.com> wrote: > > > > We use postfix as a mail queue / sending service in one of our > applications. This application generates emails with PDF attachments. Some > of the emails with PDFs get sent fine, but others seem to cause a "timeout > after DATA" error. > > > > Through reading online, I've seen answers such as adjusting the MTU size > on the network interface, etc. None of these solutions have worked. Has > anyone had this happen, do you have any suggestions to fix it? > > > > Thank you. > >
