1958 D Penny Is This Worth Sending ?

Wheat cents from the later 1950s were widely hoarded by collectors--especially cents from 1958, the last year of the Wheat cent. As such, there are vast numbers of uncirculated mid to high MS grade examples available--they aren't terribly rare. Given the photos posted, your coin would not fall into the MS higher grade range. Not worth submitting in my opinion. Check ebay for completed sales of slabbed 1958 wheat cents to get a feel for value.

although old its only worth a couple cents and every now and then you can find an AU version of it in change

There is a lot of research and experience that needs be done when looking for coins to send in for slabbing. When it all comes down to it, even the most experienced dealers cannot tell you what the grade will be when done b/c there is no science to it. Grading is all about the opinion of the graders. The following is a good video for basic information concerning how, some of the different company details of what it takes to send in a coin, and is a good START to comprehending these companies are not easy ways to making a large profit in the vast majority of cases.
18s

I agree, AU-55 and worth about a nickel.