Sealing an envelope before you meant to can be incredibly frustrating. If you have ever accidentally glued your envelope closed without adding in all of the necessary contents, try this proven way to unseal your envelope and fix your mistake.
Place envelope in the freezer
After the envelope has been sealed, lay it in the freezer.
Check the envelope every hour
Unsealing envelopes in the freezer can take a few hours. Check your envelope each hour to see if it has opened.
Remove the envelope, and insert additional contents
Once the envelope has unsealed, remove it from the freezer and put the rest of the contents into the envelope before resealing it and putting it in the mail.