The POST Compression feature is supported when both the identity provider and service provider understand SAML 2.0 POST deflate and inflate. If the service provider sends a compressed message, the identity provider needs to decompress the message and vice-versa.
Perform the following steps to enable SAML 2.0 POST deflate and inflate:
Click Devices > Identity Servers > Edit > Options > New.
Select IS SAML2 POST INFLATE in Property Type and true in Property Value. This provider will receive deflated SAML2 POST messages from its trusted providers.
Click OK.