Sending Schedules Explained


Sending schedules allow you to adjust the email send times (and days) to best match your audience.

Emails are spread evenly throughout a sending window. Let’s say you have a campaign with a sending window from 9 am to 5 pm. This makes your sending window 8 hours long. Also the campaign has 100 emails limit per day. This means that on average Mailarrow will send (100 / 8 =) 12.5 emails every hour.

In this case, very hour Mailarrow will send ±12 emails. These emails are going to be distributed evenly with some random variance of up to 30 sec. This will help our deliverability. Our software would send ±2 emails in every 5 minute timespan for this specific campaign.

Take note that this is an oversimplified scenario where you have only one mailbox, enough new prospects to enroll, there are no follow ups from previous days, there is not a high time limit on sending frequency for your mailboxes, etc. All these factors can limit the amount of emails that are being sent.

💡 There are a lot of factors that impact your email sending volume. Always feel free to reach out to support, we will help you understand what exactly is happening.

Now let’s have a look into why your campaign might not be sending emails the way you expect.

Emails for my campaign are not being sent. Why?

There can be multiple reasons why emails for your campaign are not sending.

1. You have too few prospects to start sending immediately

In case when you have only 20 prospects but 8 hours long sending window Mailarrow will send only 2 emails per hour.

2. You are outside of the sending window time (for the timezone of the sending schedule)

Adjust the sending time window and make sure that the timezone is exactly what you want.

3. You have set a high send delay between emails for the mailboxes you are using.

Set 2.5 minutes(150 seconds) delay between emails to make sure the delay length is not causing any issues.

4. You have just created a campaign and did not give Mailarrow 5-10 minutes to start sending. 

It takes 5-10 minutes for Mailarrow to start scheduling emails. This gives you the time to verify if every detail of your campaign is good to go.  

5. All prospects have been enrolled for the day and there are no follow ups to be sent.  

You can change the limit in campaign settings.

6. Email limit has been reached for the mailbox(es) associated with the campaign.

You can change the limit in mailbox settings. Be careful with this as it can have a big impact on your deliverability. We do not recommend to send over 100 emails per day even for a warmed up mailbox. 

7. Your mailbox needs to be reconnected

If you see the “Mailbox Disconnected” message when you go to the mailboxes section of the app, reconnect the mailbox and try sending a test email.