This article is of a slightly technical nature and explains Advorto's approach to managing the sending of emails.
There are two things to consider with regards to when emails triggered from the system actually get sent.
1. The delay that is configured on a particular email template
- Clients are in control of this themselves, via the email self-service features
- Delays may be set anything between send immediately and 48 hours in the future
- A default delay is also configured by either Advorto or Advorto partners (System Builder > Backoffice > Email flusher time delay). This is variable by client and is the delay that will be set when the Default option is selected for the email delay
The key benefits of having email delays are:
- Applicant tracking systems, such as Advorto, allow clients to be extremely efficient with the processing of candidates, including fully automated at some stages - sometimes too efficient! Delays in email sending may make things seem a little more "human" to candidates.
- People make mistakes - having a standard delay in your email templates, means that you've got a get out of jail free card for, e.g. 15 mins after sending a message, during which you can stop that reject email you accidentally send to 10 awesome candidates...
2. The "email flusher" frequency
The actual sending of emails from the system happens asynchronously with the act of a user actually sending the email from the Advorto system. This means that users don’t have to hang around and wait for the email to actually process and be sent. This is particularly important as users are able to send lots of emails at once.
In order to manage this, emails are initially sent to a "flusher". This gathers all the emails sent from the system, processes them and sends them to the email server to actually be sent. In order to reduce the likelihood of our email sending being throttled by some ISPs, this process happens on a scheduled basis - currently every 5 minutes.
What happens when the email delay is set to send immediately?
Due to the nature of the email flusher frequency, when an email is set to "Send immediately", this means the following:
- If an email is sent from the system and reaches the flusher 1 sec before the flusher runs, it would be sent immediately
- If an email is sent from the system and reaches the flusher 4 mins 59 secs before the flusher runs, it would be sent in 4 mins 59 secs at the point the flusher next runs
- If an email is sent from the system whilst the flusher is already running, it would depend on how many emails were being processed at the time. If only 1 email was being processed and the flusher ran in a fraction of a second, it might mean a 5 min wait for the email to get picked up at the point the flusher next runs. If the flusher was still processing emails at the time the new one came in, it would join the back of the queue and be picked up with the current flusher run.
What else might impact the sending of emails?
There is one flusher per server, so if someone for any client on the same server sends 10,000 emails, the flusher may take longer than 5 mins to actually process those. At this point, any new emails that come in will join the back of the queue. Emails are sent in the order in which they arrive, so this may sometimes mean a delay of longer than 5 mins at particularly busy periods.
Finally, all of the above only accounts for the time taken up to the point the email leaves the Advorto system (the point at which they get marked as “Sent” in the timeline). Users also need to consider the time taken to deliver the email, which may vary widely, based on all sorts of reasons, including your own infrastructure, how busy the web is at the time of day, etc.
Can we have emails really sent immediately?
We are currently considering a change to the system for our product roadmap, in which "Send immediately" emails are not sent via the above flusher mechanism, but are sent direct to the email server. This wouldn't impact the areas of email delivery outside of our control, but we would expect this to reduce the time-to-deliver accordingly.
If any clients who read this article think this would be of benefit, please leave a comment below.