Make sure that your list comprises of opted-in subscribers. These are individuals who have chosen to receive your newsletter – either they have signed up at your website, they have put their card into a bowl at an exhibition which has clearly stated they will be signed up, or you have verbally checked they are happy to have your newsletter when you exchange business cards. In my opinion, you should not send newsletters to everybody you meet at a networking event or everybody you are connected to on LinkedIn. If you purchase a list – do make sure that it is ‘clean’. Mailchimp and other tools have a very low tolerance for people they see as spamming – and in my opinion, it just isn’t worth the risk.
Once you are basically happy with the newsletter, do send some test emails and try to look at them in a range of email systems (Outlook, Gmail, Hotmail, etc..) Do be aware that there is a restriction on the number of test emails you can send, so use the preview to get it basically working.