Permission is the important first step in building a relationship with subscribers. But it’s no longer enough. You need to be relevant. Because if you're not relevant, you'll probably be deleted - maybe never to be opened in the future either. I’m not revealing any trade secrets here by telling you that inboxes are full. People don’t spend much time deciding whether to open an email (about 2-5 seconds), and if they do open it, will scan for about 8 seconds before deciding if it matters (is relevant) to them.

Your challenge is to have your email stand out amongst the other emails your subscribers are receiving. Here are some ideas:

Encourage only your target audience to subscribe.  Rather then hedging your bets by saying ‘Receive our regular newsletter’, hoping you’ll get a quantity of subscribers, think quality versus quantity. Tell people very clearly who, what, where, when and why you'll be contacting them, and then let them make an informed decision to sign up.

'How relevant is it?' answers the frequency question.  How frequently should you send your emails? It depends. There is a growing trend away from rigid monthly mailing schedules, and instead publishing when your company has something relevant to say. If it’s timely then you need to send it, if it doesn’t relate to everyone on your list, then you need to consider sending it only to the appropriate subscribers.

Relevance makes it personalised. A 'Dear Bob' appended to the top of a general mailing is not effective personalisation. Personal elements such as addressing the subscriber by name should be used when it really matters in the context of the mailing. It is more important to tailor the content to each reader, because this makes it both personal and relevant. 

Segment and tailor emails. Use information you have in your database, such as purchase history, geographic location, etc, to split out your lists. Also, let your readers help you segment - see the next tip.

Let the subscriber choose what's relevant.  Let them decide how often and what they want to receive from you. Offer the flexibility to pick areas of interest, frequency, etc. Allow readers the ability to change their selections with each mailing. Make it as easy as possible! Stay away from complicated password-protected access, these are a real turn-off and readers may just start deleting your mails rather than try to change their subscription. (Read: Required fields in your Subscribe Form: How much can you ask for?)

Send. Track. Analyse. Change. Repeat. This should be your mantra – if your company does the ‘load and send’ style campaigns, you will see a downward spiral of activity and results. An important part of the email marketing cycle is to review the information gathered from a campaign, and make changes based on the information for the next mailing.

Recent articles of interest:

How much content should I have in my newsletter? 
Ten tips for building an in-house opt-in mailing list 
The best day and time to send your newsletter 
Turn Skimmers Into Clickers 
Why Subscribers Don't Open Email