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As Fahad has already noted, if you're going to use both an in and out ACL, you'll need to account for the traffic allowed in both direction. Normally, the in and out ACE are just mirror entries, so for your example of:
in
permit tcp host E.F.G.H host I.J.K.L eq 25
out would be:
permit tcp host I.J.K.L eq 25 host E.F.G.H
Fahad also mentioned using a Reflexive ACL. These will generate a stateful mirror ACE for the reverse traffic. The reverse ACE will stay active for a short duration after seeing traffic that creates it and the it will time out and remove itself. Normally you would only use one on a trusted side of the device for generated flows. When used with a trusted side, the ACE often are made more generic, for example, any inside to outside HTTP flow will allow and ACE for the return traffic.
