You can export your contact list from your UTmail+ account and import them to your personal Gmail account. See the article on exporting contacts from UTmail+ to a .csv file.
1. Open your Gmail, Click App launcher(9 dot waffle icon) at top right.
2. Choose "Contacts"
3. Click "Import"
4. Select file (downloaded from your UTmail+ account) > Open >Import
5. The contact will be successfully uploaded to your Gmail contact list.