According to one exemplary embodiment, a method for detecting unsolicited bulk emails (UBE) is provided. The method may include receiving an email. The method may also include identifying a uniform resource locator (URL) contained in the received email. The method may then include dividing the identified URL into a plurality of component parts. The method may further include generating a tree structure based on the plurality of component parts. The method may also include generating an input string based on the generated tree structure. The method may then include calculating a hash value based on the generated input string. The method may further include determining if the calculated hash value matches a UBE hash value within a plurality of UBE hash values. The method may also include identifying the received email as a UBE based on determining that the calculated hash value matches the UBE hash value.