Our CEO doesn't want to use a transport rule to create outlook e-mail signatures because he wants to be able to edit his signature before sending an e-mail.
so we have to use a third-party tool to deploy e-mail signatures to clients. the logo we use in the signature is stored on our webserver which is in a DMZ network segment. The Server accepts http & https requests and can send https, everything else is protected by our firewall.
recipients of our e-mails don't see a logo, only if they click on "download images" they can see it. This doesn't occur when we send e-mails inside the company network.
Why does everyone else's signature seem to be visible without downloading it but our signature needs to be downloaded? Is there any security option i have to change to make this possible in Exchange, Firewall or Webserver?
I read somewhere that this is an expected behaviour, but then I can not understand why everyone elses logo is visible.
We use Exchange Online & Office365