Email Service Not Working, All Signs Point to Networking Issue

Question

We've got the NestJS MailerModule setup and working with SendGrid in the transporter. It's been actively in use for about a year. No issues. 
```ts
import { MailerModule } from '@nestjs-modules/mailer';
```
Just this past week, we've noticed that we have issues with the mailer working inconsistently. We went through a series of debugging steps, including creating new API Keys with SendGrid.

We have tested the API locally, and it works as expected. The emails are sent through SendGrid. 
```
[Nest] 26738  - 09/09/2025, 10:23:42 PM     LOG [NestApplication] Nest application successfully started +3ms
[Nest] 26738  - 09/09/2025, 10:24:04 PM   DEBUG [Logger-AuthService-generateTokenPasswordReset]: Password reset token generated successfully
[Nest] 26738  - 09/09/2025, 10:24:06 PM   DEBUG [Logger-EmailService-emailPasswordResetInit]: Sent to [Redacted]
[Nest] 26738  - 09/09/2025, 10:24:06 PM   DEBUG [Logger-AccountService-passwordForgot]: Password reset token generated and email sent for [Redacted]
[Nest] 26738  - 09/09/2025, 10:24:06 PM   DEBUG [Logger] HTTP POST /v1/account/password-forgot Data: {"email":"[Redacted]"}
```
Our currently deployed app, however, shows a different picture with no email being received. I don't have any additional info, and I don't even know how to begin debugging this any further than we already have. 
```
[Nest] 15  - 09/10/2025, 2:21:31 AM     LOG [NestApplication] Nest application successfully started +4ms
[Nest] 15  - 09/10/2025, 2:23:31 AM   ERROR [MailerService] Error occurred while verifying the transporter}: Connection timeout
[Nest] 15  - 09/10/2025, 2:27:59 AM   DEBUG [Logger-AuthService-generateTokenPasswordReset]: Password reset token generated successfully
```

Project ID: 7b51fc66-865a-4af1-b41d-bcc9f77cee30
Service: 8d8a4cfb-d517-4fe2-860e-b5134ffd9cf8

We have narrowed it down to something specific happening on Railway. Just not sure what it is.