Short answer
Reasonable verification of important information is a sensible part of matrimonial safety.
Islamic Guidance
What Islam teaches
The Qur'an instructs believers to verify important information rather than acting on unreliable reports. Verification must not turn into spying or spreading rumors.
Practical Guidance
What you can consider
Verify identity, marital status and significant claims through appropriate channels before making major commitments or financial decisions.
Sources
Qur'an 49:6; Qur'an 49:12.