smtp.dll is considered a type of Dynamic Link Library (DLL) file. Dynamic Link Library files, like smtp.dll, are essentially a "guide book" that stores information and instructions for executable (EXE) files - like certutil.exe - to follow. These files were created so that multiple programs (eg. BitDefender) could share the same smtp.dll file, saving valuable memory allocation, therefore making your computer run more efficiently.
Unfortunately, what makes DLL files so convenient and efficient, also makes them extremely vulnerable to problems. If something happens to a shared DLL file, either it goes missing or gets corrupted in some way, it can generate a "runtime" error message. Runtime is pretty self-explanatory; it means that these errors are triggered when smtp.dll is attempted to be loaded either when BitDefender is starting up, or in some cases already running. Some of the most common smtp.dll errors include:
- Access Violation at address - smtp.dll.
- smtp.dll could not be found.
- Cannot find C:\Program Files\Bitdefender Antivirus Free\web\guster\guster_00280_001\sav\smtp.dll.
- Cannot register smtp.dll.
- Cannot start BitDefender. A required component is missing: smtp.dll. Please install BitDefender again.
- Failed to load smtp.dll.
- The application has failed to start because smtp.dll was not found.
- The file smtp.dll is missing or corrupt.
- This application failed to start because smtp.dll was not found. Re-installing the application may fix this problem.
Your smtp.dll file could be missing due to accidental deletion, uninstalled as a shared file of another program (shared with BitDefender), or deleted by a malware infection. Furthermore, smtp.dll file corruption could be caused from a power outage when loading BitDefender, system crash while loading smtp.dll, bad sectors on your storage media (usually your primary hard drive), or quite commonly, a malware infection. Thus, it's critical to make sure your anti-virus is kept up-to-date and scanning regularly.