Ebay standard envelopes for postal first day covers

[fallgold4031]

Does anyone have experience in mailing postal covers using standard envelopes?  Guidelines state postcards or postal history can be mailed.  I would think that postal covers would be considered as postal history.  

[zero29zero]

Postal History or FDCs are subcategories in the Stamps category. Anything under the Stamps category I believe is eligible for ESE shipping

[fallgold4031]

Many thanks,  Doug