Oldest-wait vs fewest-emails: choosing an email routing method

Once you decide that VICIdial should spread inbound emails evenly, two Next Agent Email methods stand out: the oldest-wait methods and the fewest-emails methods. They sound similar but they optimize for different things. Picking the wrong one can leave one agent buried while another sits idle.

What oldest-wait does

The oldest-wait family covers oldest_call_finish and oldest_inbound_call_finish, which order agents by the last time they finished an email. The agent who has been waiting longest gets the next one. There are also oldest_call_start and oldest_inbound_call_start, which order by the last time an agent was sent an email and even out the totals over the shift.

In practice, the finish-based methods feel fair to agents because nobody who just wrapped a tough email gets slammed again immediately. The start-based methods feel fair on paper because everyone trends toward the same total. Both treat the wait clock, not the running count, as the deciding factor.

What fewest-emails does

The fewest-emails family is fewest_calls and fewest_calls_campaign. These order agents by how many emails they have already received, least first, either for that specific Ingroup or across the whole Campaign. The agent with the lowest running count gets the next email regardless of how recently they finished one.

This is the method to reach for when your top goal is an even tally at the end of the day. A fast agent who clears emails quickly will keep getting fed until their count catches up with everyone else's. The trade-off is that the count knows nothing about timing: an agent who just closed a long, draining email can be handed the next one immediately if their running total is still the lowest in the group.

Notice that the count only includes emails taken from that scope. An agent who spends part of the shift on calls rather than email will show a low email count and start collecting more of them when they return to the queue. That is usually what you want, but it is worth knowing if your team is blended between calls and email through the day.

How to choose

The decision usually comes down to whether you care more about wait time or about a balanced count:

• Use an oldest-wait method when your agents handle emails at roughly the same speed and you want the queue to feel fair in the moment.
• Use a fewest-emails method when speeds vary a lot and you want everyone to end the shift with a similar number handled.
• Pick the inbound-group variant to scope the ordering to one email group, or the campaign variant to balance across the campaign.

A small but real difference: the start-based oldest methods order by the last time an agent was sent an email, while the finish-based ones order by the last time an agent finished one. If your emails vary wildly in how long they take, the two can rank agents differently. Start-based tends to even out totals; finish-based tends to protect whoever just did hard work. For most teams either one feels fair, so do not overthink the pair.

flowchart TD
  A["Goal for the email queue"] --> B{"What matters most?"}
  B -->|Fair wait time| C["oldest_call_finish"]
  B -->|Even daily totals| D["oldest_call_start"]
  B -->|Flat running count| E["fewest_calls"]
  C --> F["Scope per group or campaign"]
  D --> F
  E --> F
  F --> G["Set Next Agent Email"]

If you would rather steer more work toward your strongest people instead of spreading it flat, look at routing by user level, and for the wider context start with the inbound email and chat guide. The same fairness questions show up in Skills-based routing for calls, and the Agent rank you set feeds the rank-based methods. When an Agent finishes, they apply a Disposition and rejoin the pool. Running this on a managed VICIdial box means you skip the email-parser setup; our pricing page has the details.