• A subject line should be as short and descriptive as possible. The subject line should be informative and true. If your from name and address are not branded, the subject line should also provide assurance that the email comes from a trusted source. A general rule of thumb is to keep subject lines between 30-50 characters.
• A strong offer can be put right in the subject line. Evaluate your content to understand the likelihood of your message hitting spam filters, particularly if a high percentage of your list is at corporate domains. Corporate domains rely more on phrases or words that have been “tainted” by the spamming community. The major web-based email clients focus on your reputation more than your content.
• The from name and address can be as important as the subject line. A strong offer can be put right in the subject line, but it is important to use punctuation and grammar carefully to ensure that you are not perceived to be a spammer by the receiving ISP.
• The ‘from’ name and subject line should work in tandem. The ‘from’ line should communicate who you are as the sender. Do your best to not change this entry frequently and make it recognizable so that recipients understand that the email was sent by a reliable source.
• If you are cross promoting a sister brand, use the subject line to introduce the sister brand and do not change the ‘from’ address of the originally subscribed-to brand. Any other ‘from’ address is likely to increase complaints. For more information on cross promoting sister brands, please see our recent post on promoting sister brands.

That said, spammers use various tactics to fool people into opening their emails. Spammers often use words that announce a big incentive or urgency. We suggest testing certain keywords or alternative words to optimize your subject lines.

• Some key words and phrases such as “act now,” “trial,” “quote,” and “guarantee” can be tested against “complimentary,” “estimate,” “be our guest,” and “giveaway.”
• While “Free” performs well in subject lines (see Experian CheetahMail’s Free Shipping Report) you might try using “our treat” or “on the house” to see what works best for your brand.
• Avoid excessive punctuation — exclamation points, multiple periods (…), dollar signs ($$), etc.
• In the past putting full words in ALL CAPS was considered equivalent to shouting. Using all caps is a practice used by spammers. Test the use of all caps and monitor any drops in open rates potentially due to filtering.
• Using ‘Re:’ at the beginning of a subject line falsely leads the recipient to think the email is a reply to a previous email. This is a misleading tactic. This tactic is not CAN-SPAM compliant and creates a poor customer experience. If the recipient feels duped into opening an email, you might see an increase in abuse rates or unsubscribe requests.

Just a few little words/phrases in your subject line can make or break the success of your email marketing campaign, not just by impacting open rates but affecting deliverability too. To learn what works best, test. Following these subject line best practices can save your client from losing both excellent reputation and good subscribers.

• Now is the time to emphasize the “please add us to your address book” requests and instructions during the email registration process and in welcome emails. Not only will you get added to user whitelists which overrides ‘junk’ or ‘spam’ folder delivery, but also recipient response rates should be better, as well as brand perception, because images are displayed by default. A new trend for marketers is to consider sending a dedicated message solely to drive address book adoption in advance of the holidays. For example, “We are going to have some fantastic deals during the holidays. Add us to your address book to make sure you don’t miss them.” In light of the recent Facebook ‘Messages’ announcement, it is also now important to use such a dedicated email to request users become a ‘fan’ or ‘like’ your content.  [See example below]
• If you have a group of recipients who haven’t been mailed in a long time, before mailing them all at once, consider testing small segments to gauge complaint and bounce rates and make creative and segmentation adjustments with subsequent campaigns to ensure these metrics don’t become a risk to your overall messaging reputation.
• It is critical to maintain the same ‘from’ addresses and formulate subject lines that highlight the email’s ‘call-to-action’ and is not too ‘cheeky’ that it could be confusing or misleading to recipients where it may lead to user complaints.

In 2009, holiday email volume rose, increasing over  26% from the 2008 holiday season. We can predict this trend to continue for the 2010 holiday season meaning the ISPs will be working in overdrive to ensure all relevant and legitimate email is delivered into the Inbox while keeping out the large amount of true spam. Following these holiday best practices, and others such as maintaining ‘engaged’ users will help keep your clients’ IP reputation strong, your Inbox delivery rates high, your targeted customers happy and ultimately your revenue numbers up.

Even without seeing the new Messages user interface and only seeing ‘Zuck’ and ‘Boz’ demonstrate a portion of it yesterday, it seems apparent that the Facebook email application is not a ‘Gmail killer’ or intended to be competitive with any full-fledged email client webmail or software program. But what it does have that no one else has captured is the notion of a truly personalized messaging platform.

However, my wake-up moment on the webcast yesterday was when they disclosed that any user can change their privacy settings to restrict emails just to their friends, friends of friends, or everyone. More importantly, should the user tighten their settings to exclude everyone, Facebook will bounce all emails from that sender to that user. In other words, if a marketer does not have a ‘fan’ or ‘friend of friend’ relationship with that user, then they should assume the address will bounce.

It is important to note that there apparently will not be a ‘junk’ or ‘spam’ folder for these unrelated messages to be filtered into, just an ‘other’ folder that isn’t designed to be a ‘reputation’ or anti-spam filter since all emails from unrelated senders will just bounce away. There is no ISP ‘Batphone’ when trying to resolve deliverability to ‘friends’, so even the most experienced and skillful deliverability team in the world won’t be of much assistance with most Facebook deliverability problems.

The clear conclusion from this is that marketers should not attempt to collect an @facebook.com email address without making a strong effort to first ensure that the user is a ‘fan’ or logs in through Facebook Connect.   This should require Facebook-specific language on the email registration or transaction page, or most certainly on the post-registration or transaction page. Because if you don’t do something to befriend these users, then your ‘Messages’ may not get there at all.

Here’s a personal story about why it doesn’t make a lot of sense to bounce remove after the first attempt.

I purchased my personal domain name in 1998 and have used it for select personal email relationships ever since. I had a problem with my domain registrar a couple years ago that involved them accidentally expiring my domain without notifying me. It then took weeks to get it fixed. In the meantime, all personal email to me hard bounced. Some of my most important contacts reached out to me through other channels, a few even sending snail mail informing me of the bounced email.

While this situation is rare, it is just one of many reasons why emails hard bounce and yet will be valid once again in short order.

In the past, ISPs used to focus on hard bounces as a critical anti-spam metric. With today’s sophisticated filters focused primarily on complaints and other data, very few ISPs see a reasonable (<5%) hard bounce rate as an indicator of spam as long as the other performance metrics are also in line with legitimate email.

Some additional tips when considering bounce removal rules:

1. Every ISP is different, therefore a liberal bounce rule at less sophisticated ISPs (like those without real-time complaint data) could result in deliverability problems.
2. Re-mailing bounces again is not the same as ‘re-trying’ a message. If the address is invalid now, it likely won’t be valid again the same day or even a few days from now. Wait a week or more before re-mailing that user.
3. Never re-mail bounces more than a few months old. Some ISPs turn bad data into spamtraps, which are used as an anti-spam filter. In some cases, ISPs will share defunct addresses with 3^rd party blocklists like Spamhaus. In other cases, an ISP may recycle that address to another user.
4. If the relationship is really important (or if you have the resources), consider a personalized snail mail effort following a bounce. I was pleasantly surprised about the letters from my commercial relationships and valued those relationships even more as a result.

From a deliverability perspective, this feature once again proves that building a good sender reputation that includes regular customer engagement is of the utmost importance. If users are consistently marking your mail with increased priority, then the sender’s reputation will likely improve. If users are consistently marking mail with decreased priority, the sender’s reputation will likely degrade. While the importance of these new priority settings are mainly user-specific, if too many people push the ‘less important’ button, then Gmail’s algorithm will take this into account and may push those senders email into the “Everything else” section or possibly into the Spam folder.

How Priority Inbox works:

Priority Inbox analyzes incoming mail, giving it a ranking and sorting it into four customizable sections: “Important and unread” (or just “Important”), “Starred” and “Everything else.” “Important” messages are intended to be the most relevant or relationship-oriented, and sit at the top of the screen. Next is the “Starred” section which are messages the user manually flags or sets up as a recurring indication of importance. “Everything else” includes those messages that may not be from an established contact or regularly engaged with before.

Gmail will automatically determine which of your messages are ‘Important’ based on their algorithms and a few other aspects, including:

• Who sent the email. For example, if you email Bob a lot, it’s likely that messages from Bob are important.
• What keyword terms it includes. If you always read messages about soccer, a new message that contains those same soccer words is more likely to be important.
• Other actions such as: replying, using ‘Stars’, archiving, regularly opening, and deleting.

It will also be important for the user to interact and train the new Priority Inbox by using the + and – buttons or the ‘important’/’less important’ buttons. This will help the Priority Inbox learn which messages the user cares most about, in addition to teaching the algorithm about mistakes with mail marked as more or less important.

The new feature, like many of Google’s platform enhancements, is free to all Gmail users who opt-in. It is important to note that the Priority Inbox is a feature that can easily be disabled and is fully customizable for each user. From the Priority Inbox tab on the Settings page, a user can decide how many mail items each section should display (5, 10, 25, or 50), and which view is default. Additionally, even if the user keeps the Priority Inbox enabled, a tab for the ‘regular’ Inbox is still a choice on the left navigation pane and can be referred back to at any time.

If the user has not customized any of the settings and then opens a message within the “Important and unread” section, those opened emails will then move to the “Everything else” section once the window is refreshed. A user can change this by customizing the settings so that even unopened email that would normally be in the “Important and unread” section are listed in the “Important” setting instead. This process is illustrated in the two screen shots below:

What it all means:

In general, the Priority Inbox should help senders reduce abuse complaints and default Spam foldering since users will have more options to express their preferences with Inbox placement instead of pressing the ‘Spam’ button. In addition, Gmail should now find it easier to deem questionable email (aka; ‘bacn’) as ‘Everything else’ as opposed to placing it by default in the Spam folder. However, for senders whose email is usually prioritized in the Inbox, yet is now in the “Everything Else” section, this change may hurt messaging performance. Over the next few months, the CheetahMail deliverability team will track delivery performance changes at Gmail and report back on any noticeable differences Priority Inbox has made on client delivery efforts.

For more information, refer to: http://mail.google.com/mail/help/intl/en/priority-inbox.html