Synthasite does bulk submissions of your published sites. However, you can submit your own site map to Google and other search engines if you like. Here are the instructions:

You first need to have your site "verified" by Google before you can continue - instructions here. Once your site has been "verified" you are ready to add a Site Map.

1) Go to http://www.xml-sitemaps.com/
Type in your URL e.g. http://yoursitehere.synthasite.com/
Leave all the other stuff on the page as is and then click on the start button. Next - click on the download XML sitemap.

2) Go to your site login and open your site.
Open the file manager and upload the XML sitemap that you just downloaded. N.B. Update your site.

To submit your site with Google only go to step 3, otherwise you can jump to step 4.

3) Go to Google Webmaster Central. On the dashboard select "Add Sitemap" Choose type e.g. (Add general web sitemap)
You should see an input box asking for your XML sitemap file.
Type in recources/sitemap.xml in the box provided.
The full address will look like this:
http://yoursitehere.synthasite.com/recources/sitemap.xml

You should get a confirmation message that says: "You have added http://yoursitename.synthasite.com/re.... Reports may take several hours to update. Thank you for your patience!"
Processing Sitemaps may take some time. Check again later to see if pages from your Site maps are included in Google's index. On the Google Webmaster Tools Site maps page: If everything has gone correctly, eventually you will see the status column say "OK"

4) An easier way I found, and you can skip step 3, is to go to
http://www.sitemapwriter.com/notify.php. Enter your URL e.g.
http://yoursitehere.synthasite.com/recources/sitemap.xml
and click on "submit". Your site will now be submitted to Google, Yahoo, Ask, Moreover and Live.
I was crawled in under 4 days using the above method.