Why emails are blocked by Gmail and how to resolve?

What is the issue?

Gmail can block and bounce emails when it is sent using programs such as Apps Script or add-ons

Context

When users of Gmail are trying to send email through apps script program or using add-ons like Form Director, Fillable Document etc, Gmail may block or bounce these emails. Read below to see the reason for such blocking and how to resolve it.

NOTE: Our addons use only apps script mail services to generate emails

When can this happen?

Emails could be blocked for one of the following reasons

Google suspects spam/ phishing
Too small email
Malicious attachment
Incorrect Mail Records with Domain Registrar

How to resolve?

One needs to understand the cause of the issue first to resolve the issue. Once the cause is identified, follow the resolution steps below to resolve for good.

Correcting Invalid Mail Contents

If the content is too small or having malicious attachments, ensure that your source program of the email is making good content. For example, .com or .exe files should never be attached in the email.

Correcting Mail records in Domain Registrar

Ensure that your SPF, DKIM and DMARC records with your domain registrar is configured correctly so that email gateways can verify the authenticity of the email

SPF - Follow this article and implement all steps to set up SPF
DKIM - Follow this article and implement all steps to set up DKIM
DMARC- Follow this article and implement all steps to set up DMARC

If any of these records in your domain registration is incorrect, you need to correct these and then try again. Note that your domain provider might take up to 24 hours to propagate the changes.

If you have completed all DNS verification(SPF, DKIM, DMARC) recently, then you have to wait 24 hours for the changes to reflect in your Domain.

Do you follow all steps mentioned above correctly and still is email keep bouncing or getting blocked?

Reach out to Google Workplace Support
Reach out to your Domain Registrar for Support

Google Workspace Support

Both Gmail service and Apps Script (add-ons are built using Apps Script) are from Google, and hence reach out to Google Workspace support to find why Gmail is blocked.

Google has the obligation to support you as they are providing the Gmail service which is getting blocked. You might need to get on a screen share call to sort things out.

Domain Registrar Support

Your domain registrar has the obligation to support you on setting up SPF, DKIM and DMARC correctly. Identify your domain registrar (e.g GoDaddy, Cloudflare, Google Domains etc) and reach out to their support. You might need to get on a screen share call to sort things out.

Final Note:

Configuring DNS record is quite a challenging task. You need expertise, patience and seek out support from Google and your domain registrar. From Form Director side, we do not have much to do except to educate on what is required to be configured.

Once you have set it up SPF, DKIM, DMARC records successfully, it will be running just fine for the rest of the life of the domain. 😀