Clinton set up a personal account for non-classified emails, and SOME classified emails slipped through. What she did was technically legal, except she didn't ask for permission, The main issue was that the server she used didn't have proper security, which while technically violates the law, didn't warrant charges. The use of a private server without clearance, in and of itself, is not something that would warrant criminal charges unless there was some other crime being committed connected to it.
What Trump did was STEAL classified documents, including documention on both the US nuclear program and those of two key allied, and keep them in an unsecured room at his golf resort. He ignored the National Archives' demands that the documents be returned for over a year, and then LIED to a federal judge by having his attorney file a sworn affidavit claiming that the all the documents had been returned. The national archives suspected he was lying, due to the fact that there were still thousands of documents still not accounted for, and asked the FBI to intervene with a search warrant, and they got one and raided the property, collecting well over 40 boxes that Trump claimed UNDER OATH that he didn't have.
What Trump did was STEAL classified documents, including documention on both the US nuclear program and those of two key allied, and keep them in an unsecured room at his golf resort. He ignored the National Archives' demands that the documents be returned for over a year, and then LIED to a federal judge by having his attorney file a sworn affidavit claiming that the all the documents had been returned. The national archives suspected he was lying, due to the fact that there were still thousands of documents still not accounted for, and asked the FBI to intervene with a search warrant, and they got one and raided the property, collecting well over 40 boxes that Trump claimed UNDER OATH that he didn't have.