Replace all URLs

[tsilveruits]

Without enabling URL filtering, would it be possible to rewrite all URLs received in emails on the external listener, say, if you wanted to just route them all to your own proxy? This wouldn't require enabling the URL filtering service on the ESA, which add processing overhead. I researched using message filters, but I would need to capture the URL and reuse it, and I see no way to do that. In content filters, and in message filters, I suppose, you could, as the ESA User Guide says, rewrite a URL like this, http://custom_proxy/$URL, to be, http://custom_proxy/http://example.com.

[Robert Sherwin]

This could be done w/ some trial and error to achieve what you are needing...  similar to strip URL --- you would need to use something similar to this logic:

Create the following message filter:

URL_Replaced:

if true {
edit-body-text("(?i)(?:https?|ftp)://[^\\s\">]+", "URL REMOVED");
}

The above filter will be applied to all messages, received or sent by the appliance. You can add a condition to filter only incoming mail.

URL_Replaced:

if recv-listener == "IncomingMail" {
edit-body-text("(?i)(?:https?|ftp)://[^\\s\">]+", "URL REMOVED");
}

The above filter will be applied to messages received by the listener named IncomingMail.

The string URL REMOVED will replace the url in the body of the message.

This will take any/all hyperlinks in the email, and change to “www.nhl.com”, or edit as needed:

change_url: if true {
edit-body-text("(?i)(?:http?|https?)://[^\\s\"]+", "http://www.nhl.com");
}
.

Take your pick how you would want to work in for your environment.

-Robert

[tsilveruits]

Thanks, Robert. That is in the ESA User Guide, but I want to re-use the matched string (i.e., the URL). How would I do that? These examples demonstrate replacing a string with another string.

[Libin Varghese]

I do not see this as a configurable option available currently which would allow you to re-use the string.

The matched string can only be replaced with another string.

Regards

Libin