Which Email Service Provider should I use as Email Mailbox for cold email

title: Which Email Service Provider should I use as Email Mailbox for cold email
description: Choose the right email provider for your cold email needs.

Overview

Choosing the right Email Service Provider (ESP) is one of the most important decisions for cold email success. The wrong provider can get your mailbox banned, send your emails straight to spam, or block you entirely before you even start.

We strongly recommend using Google Workspace or Microsoft 365 Outlook only.

Why Google Workspace and Outlook?

These two providers are built for business communication and offer the best deliverability, sender reputation, and infrastructure for cold emailing. They handle volume better, have robust spam-filtering intelligence, and are trusted by email providers worldwide.

Using other email service providers puts you at significant risk of getting banned or blacklisted, and you must know exactly what you're doing before using them.

Providers to Avoid (and Why)

Zoho Mail

Zoho will usually either deliver your emails straight to spam or simply block your mailbox as soon as you send more than 20–30 emails per day — especially if your reply rate is less than roughly 20%. This makes it unreliable for any serious cold email campaign.

Hostinger

Hostinger will not let you send cold emails at all. It detects email warm-up activity from SalesBlink (or any other tool) and blocks your mailbox immediately. There is no workaround.

Titan Email

Titan Email is designed around security, not cold email outreach. It does not provide proper SMTP/IMAP support, and emails sent through Titan frequently land in spam. For cold emailing, it is highly likely you should never use Titan Email.

AWS SES, SendGrid, and SMTP-Only Email Marketing Services

These services can work, but only if your goal is one-way communication — such as notifying your lead list with an announcement or a broadcast email — rather than expecting replies, conversations, or sales.

You must know what you are doing before using them. In the case of AWS SES, SendGrid, or other SMTP-only marketing services, you are also required to include an unsubscribe link in every email because it is explicitly mentioned in their terms and conditions, which you accept when creating an account on their platform.

If you are running reply-driven outreach, these services are not recommended.

The Bottom Line

Do not cheap out on your mailboxes. It makes no sense to send emails that go to spam or are never read by your leads. Your goal is to get your emails opened, read, and replied to — and that requires using the best ESPs available, which are Google Workspace and Outlook.

In the end, reply rate really matters. If your reply rate is higher than what your email service provider expects, you might stay safe. But if your reply rate is low and you're using a risky provider, it will almost certainly become a problem.

Updated on: 03/07/2026