Starting it back up again - Cold emails

So last year I had a fairly good response rate to cold emails, but I'm kind of in a strange situation and I'm not really sure what to do.

Doing a teaching program abroad (think Teach for America for English speakers in a non-English speaking country). It is a one year program, but the option to renew. Last year, I was planning on going back after my first year, so in March/April of 2012, I started to reach out to various alumni, got pretty good response rates, but ultimately decided to stay in the program another year. I want to start reaching out to them again after not having contact for about a year.

How should I go about doing this? Should I use the same email thread? For the ones who weren't able to help me last year, should I see if there's something they can do this year? Should I explain the reason for not contacting them?

This would be my sample format, thoughts?

Mr. XYZ,

NOT SURE WHAT TO WRITE IN THE OPENING LINE. I ultimately decided to stay another year in COUNTRYNAME to improve my LANGUAGESKILL and teach for another year as a part of COMPANYNAME. I am planning to return this August. I am wondering if you can provide any insight into XYZCOMPANY. I know most of the recruiting takes place on college campuses. Do you work alongside anybody coming from a non-traditional background such as mine? Do you have any suggestions for someone looking to break into consulting? I'm happy to talk on the phone if you think that is easier than responding by email.