Most message-to-target campaigning tools send emails on behalf of supporters. That’s the standard model across the industry. A supporter fills in a form, clicks “send”, and the campaigning platform delivers the message to the target using its own mail servers.
This is how Proca’s Message-to-Target (MTT) usually works too. We use professional-grade email infrastructure to deliver messages reliably, personalise them, and manage things like delivery speed, timing and reporting.
But in light of the European Parliament’s recent attempts at server-level filtering and archiving of campaign emails, we’re looking at going back to some old-school solutions. That’s where client-side sending comes in.
What client-side sending actually means
In this mode, the email isn’t sent by Proca at all. Instead, it’s sent directly from the supporter’s own email account. Here’s what the supporter experience looks like:
- A supporter lands on the campaign action page.
- They fill in their contact details.
- They click “Take action” or “Send email.”
- Their email client opens automatically (Gmail, Outlook, Apple Mail, etc).
- The email is already pre-filled with the addresses and suggested message.
- The supporter can edit the text if they want.
- They click send and their email is immediately sent to its intended recipient.
From that moment on, the email behaves like any normal message sent from their inbox.
Pros of client-side email sending
This approach may feel a bit old-school and low-tech, but it has some serious advantages.
1. It’s extremely hard to filter
When Proca sends emails on behalf of supporters, they come from professional email servers. That works well in most cases, especially with features like message variation, drip delivery and message digests. But mail systems can still detect patterns when thousands of emails originate from the same infrastructure.
With client-side sending, each supporter sends the message from their own email provider, so the emails originate from thousands of different servers, like Gmail, Outlook, Yahoo, company or university mail servers, etc. This makes mass filtering much harder.
From the politician’s perspective, these look like individual messages from real constituents.
2. Replies go directly to the citizen
Another advantage: replies go straight to the supporter. When a politician’s office sends an automatic reply or – rarely – a personal response, it lands directly in the citizen’s inbox.
This strengthens the feeling that the message came from a real person contacting their representative, not from a campaign system. It can also increase engagement, because supporters actually see responses from political offices.
3. It’s cheaper to run
There’s also a practical benefit. When Proca sends campaign emails through our own infrastructure, we rely on professional email providers. Those providers charge for sending large volumes of messages. With client-side sending, the supporter’s own email provider sends the message. So there’s no delivery cost for the campaign.
Cons of client-side sending
Client-side sending solves soms technical problems, but it introduces others.
1. No personalised emails for multiple targets
Normally, Proca can personalise emails for each recipient. For example, if a campaign targets multiple politicians, the message might automatically include information such as their name, custom salutation, and a form of address appropriate to their gender in gendered languages.
With client-side sending, that’s not possible. Instead, one email is sent to multiple targets using BCC. The same message goes to everyone, without individual personalisation.
2. No drip delivery
Another limitation is delivery timing. With server-based sending, Proca can stagger messages over time using drip delivery. This avoids overwhelming inboxes and helps campaigns stay visible for longer.
With client-side sending, the email is sent the moment the supporter clicks send. If thousands of supporters act at the same time, e.g. during campaign launch, the target may receive thousands of emails in a short period. That can increase the risk of inbox overload.
3. Target email addresses become visible
Because the supporter’s email client opens with the message prefilled, the recipient addresses are visible to the user. That’s usually not a problem. But in some cases it can cause confusion.
For example:
- the official email address might look unfamiliar or “wrong”,
- the address might differ from the public contact page (e.g. it was given to a campaigner specifically for campaign communication purposes),
- some campaign targets prefer not to have their email widely visible,
So campaign organisers need to consider this when choosing the sending method.
4. Some email clients don’t cooperate
Client-side sending depends on the supporter’s email software working correctly. Occasionally people have email clients that are misconfigured – especially corporate Outlook installations. In those cases, the prefilled email may not open correctly, or sending the message may fail. This doesn’t happen often, but it’s a known limitation.
What we’re working on next
We’re currently improving the client-side sending model in a few ways.
1. Better action tracking
Right now, we can reliably track when supporters fill in the form, click “take action” and open the email window. In most cases, this is enough data to go on when assessing the campaign performance.
But once the message is inside the supporter’s inbox, we can’t directly see whether they clicked send. That’s a limitation of how email works – we obviously cannot access individual inboxes.
One workaround is adding a campaign email address in BCC. If the message is sent, a copy arrives at the campaign inbox. We’re exploring ways to automate this so campaigns can get better reporting on actual message delivery.
If this is something you’d like to help test or develop with us, we’d love to hear from you.
2. Hybrid sending mode
Another improvement we’re exploring is a hybrid sending system. In this model, if a supporter’s email client isn’t properly configured or buggy, they would see two options:
- Send from your own email client,
- Let the campaign send the message on your behalf.
This ensures the action always works, even if the supporter’s device setup is incomplete or unusual.
When should you use client-side sending?
Client-side sending is not always the best option. From a user experience perspective, it’s a bit less smooth. Opening an email client feels slightly more manual than simply clicking “send”. Each extra step risks the supporter getting distracted and dropping off.
But in can also be incredibly useful – especially to counter aggressive email filtering used by your campaign target. Thousands of messages coming from thousands of real inboxes are simply very difficult to filter out.
At Proca, we try to give campaigners multiple ways to reach decision-makers. Sometimes that means sophisticated delivery systems with advanced features, like our state-of-the-art Message to Target tool. But sometimes it means relying on a simple principle: let citizens speak from their own inbox.
Client-side sending may feel a bit old-school. But when the goal is making sure politicians actually hear from their constituents (even when they do their best not to!) it can be one of the most effective tools available.