Note: This post is part of a special holiday blog series created by our Expert Services Team at SendGrid to provide information on how to prepare and get the most out of your email campaigns this year. Many marketers view email campaigns as an opportunity to grow revenue–especially during the holiday season. But this perspective doesn’t quite capture the entire picture and can actually harm your sending reputation. Email inbox filters are trying to make sure they are keeping inboxes full of only the most wanted email. How do you make sure your email program looks as good as possible to these filters while you try to tap into your recipient base this holiday season? Following the tips below ensures that as you increase email sends with customized holiday emails, you don’t sacrifice deliverability. Plan ahead and ramp up your email Do your holiday email campaigns require sending more email than normal? Plan ahead. If you’re shooting for a 5x volume send on Black Friday, ramp up prior to that date by only increasing your normal daily sends by no more than 5% of that old “list” you don’t normally send to. As always, if this “list” is purchased, borrowed, rented or unfairly acquired in any way, don’t bother. Even with less than 5% a day, these “purchased” lists are meant to be detected and could negatively affect your entire mail program. Most inbox filters are quick to punish and long to forgive. Be cautious of pushing this limit and remain aware of your target metrics. For more tips on how to grow your email list the right way, read over our interactive How To Grow Your Email List best practice guide. Send to your top engagers first Try to approach each day of sending as an email program “warm up.” By this I mean send to your most engaged recipient’s first within each day. Then, send a second wave to the recipients that indicate lower engagement (haven’t opened/clicked/purchased in a while) later in the day. Trickling in those “less likely to engage” senders early in the day won’t bring their chance up to get let into the inbox. Sending to those less likely to engage too early (and mixed with your highly engaged users) actually increases the chances of your emails going into the spam folder. Add IPs if necessary If you dramatically increase your sending volume, you may need to add and warm up an additional IP (or even another domain) now. There are different reasons to also consider this based on the difference in mail campaign types you plan to send. If that is the case, a lot of the previous tips will apply, but this extra step of warming up your domains or IPs needs to be planned for as well. For a full guide on how to warm up your IP, check out How To Warm Up An IP Address. For more tips on how to avoid the spam folder, check our Top Tips and Tricks to Stay Out Of The Spam Folder. And good luck sending this holiday season!