Envelopes may be opened manually or electronically. Manual letter openers are made from plastic, stainless steel, gold or titanium, and are sold on Amazon, OfficeMax or other online stores. PitneyBowes sells a high speed automatic letter opener, which opens 50 to 400 letters per minute, while other electronic letter openers are also available from Staples.com, or other office supply stores.
Envelopes can also be opened with the help of steam. Dangling the closed letter over steam for 15 seconds helps to melt the glue, allowing the envelope to be opened without tearing it. Alternatively, the envelope may be placed in a freezer for several hours, inside a plastic bag if necessary, to keep it from getting damaged. This hardens the adhesive and with the help of a letter opener or knife, the envelope may be opened easily without ripping it.
The steam and freezer techniques are good options if a letter needs to be opened and resealed. It is particularly helpful if something has to be added to the envelope after it's been sealed, or the contents of the envelope require alterations, and there is not another fresh envelope available to use.