Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to avoid the gmail spam filter [title] Create your own email list. [step] Rather than purchasing an email list from a third party or using a robot, build your list from scratch. The only people on your email list should be people who want to receive your messages.

Ending1: [title] Begin by accepting spam free daily and monthly. [step] The number one and most effective part of developing a programming engine is accepting spam free monthly. Ending2: [title] Decide what to do with your messages. [step] " spam " emails should be read through for a minimum of 15 minutes before being sent, then " share with my friends " until 10 minutes later. Ending3: Whoever manages the list does not need to know that you repost e-mails on your own. [substeps] If you're not a robot, choose a design and program that's different from your other email list. Ending4: [title] Let your recipients double opt-in. [step] Even if the only way to be added to your list is to sign up online, make sure your mailing list service delivers a confirmation message so the customer (or potential customer) can confirm their membership.

Answer format: ending1/ending2/ending3/ending4