When to Use Email vs. Slack: Team Communication Tips

As more companies transition to virtual environments and distributed teams become more common, team communication needs may undergo similarly drastic changes. Email is the global standard for online messages—particularly in business— and of the many email management systems, Gmail is probably the most widely used. (As such, this blog post uses email and Gmail interchangeably.) Even so, Slack continues to grow as a popular platform for communication among teams. 

Although comparing Slack vs Email for different occasions offers important insights, integrating both platforms allows teams to use traditional messages as well as more immediate chat options with Slack. Instead of choosing one communication channel, using them together can enhance your team's collaborative capabilities and benefit productivity.  

Over this post blog, not only we'll be identifying pros and cons in the use of Email vs Slack (and viceversa) but more importantly, we'll go over how you can boost your team's performance by combining these two powerful communication tools.

Email vs. Slack: Create Team Communication Standards

In virtual working environments, some team members cling to the nostalgic ease of walking into a coworker’s office for a quick question. Others cherish the increased productivity remote work offers by simply silencing chat and email tools rather than fending off face-to-face interruptions and distractions. 

Problems emerge when team members have different communication expectations and habits. Establishing protocols is vital for maintaining—and increasing—productivity among teams.

Obtaining a simple team consensus can prevent frustrations caused by delayed responses. Informing other team members of messaging preferences across different channels also encourages organized information sharing, thereby boosting employee collaboration and efficiency. 

By comparing Email vs. Slack, teams can determine which platform works best for different situations and learn to optimize both platforms. After all, both platforms offer different, but equally beneficial, features. 

When To Use Email vs. Slack?

Even though integrating the two platforms offers the most benefits by improving clarity in your messaging to boost team productivity, some individual cases may require you to choose between the two. Ultimately, each platform supports a specific form of communication, so platform usage will differ based on the type of information you need to send.  

Slack Over Email 

Slack is a chat-first tool meant for interactions that rely on quick responses in a more casual tone. Instances in which users may prefer Slack to Gmail include, but are not limited to:

• Urgent messages
• Real-time collaboration
• Organizing team bonding:
  • Daily watercooler moments
  • Weekly team-building chats
  • Quick brainstorming sessions

Internal communication and collaboration may be easier when using Slack vs Email. Searching for team members is easier in Slack, when Gmail addresses may not represent the recipient’s name. Also, even if you have never messaged a Slack user before, the interface still allows you to find them easily. In contrast, it’s only easy to find someone in Gmail if you have emailed them in the past.

Slack is the right tool for an informal, user-friendly form of internal communication. This makes it better suited than Gmail for casual conversation-like messages and company-based communication. 

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Even if you decide to use Slack as your main communication channel, there are many downsides to using it by itself. Gmelius gives Slack extra features and implementations that can help their users to communicate easily with team members who prefer Gmail. 

Gmelius can help integrate your Slack and Gmail platforms to expedite team organization and information sharing. This combination also allows members to:

Change Gmail assignment statuses within Slack

Assign Gmail tasks to teammates from Slack

Reply to emails from Slack

Sync Gmail notes with Slack

Integrate email shared inboxes with Slack

Asynchronous communication refers to messaging that does not happen simultaneously, or when messages do not require immediate responses. Senders and receivers can take time to reply with the correct information. This kind of messaging operates under rules opposite to the chat-first toolset Slack provides. Despite its native chat format, Slack can also act as a method for asynchronous communication with the implementations Gmelius offers. 

Email Over Slack

Gmail is the best platform for conveying detailed, precisely worded messages. Senders can take the time to provide all the necessary information compiled in one email, offering a perfect example of asynchronous communication.

Since it takes longer to craft a well-written email than a quick chat reply, this communication medium is better suited for thorough or formal messages that require less immediate replies. 

Email also offers an easy way to keep track of threads and scroll back through older conversations. This searchable history is one of email’s greatest strengths. Catching up on conversations in Slack can be a hassle due to its fast, chat-focused nature.

Gmail threads your messages together to provide a concise, chronological order of messages for easy-to-find information.

Email is best used for long-form or official external communication and organization. While you can search for a message in Slack, email gives users a filter feature in which they can search for messages based on:

• Sender
• Subject
• Size
• Date
• Message
• Attachments

Filtered searches help users organize their mailboxes and find important messages easily. 

Gmail offers analytics that can benefit teams, but the native analytics tools in Google Workspace are limited. To give leaders a baseline reading on productivity, Gmelius boosts Gmail analytics with more features and implementations. Whether your team decides to use Slack or Gmail as their main communication platform, these analytics will prove beneficial. When replying to an email, either from Slack or Gmail, tracking the average time to reply helps identify bottlenecks and other obstacles to successful projects.

Gmelius also gives Gmail more automation for workflow organization. For team managers, workflow automation is essential to keeping up with the influx of projects and tasks. Using Gmelius' “if this, then that” logical process, you can:

• Change assignment status
• Send automated replies
• Assign tasks to teammates
• Set time-based targets with SLA rules
• etc.

Email vs. Slack?

Ultimately, most team members will prefer one platform over the other. Consequently, team members will split their usage between both platforms, muddying the clarity of shared information—unless teams can learn to embrace the benefits of both. Since each tool offers different strengths, using both platforms for different reasons maximizes your communication and collaboration benefits. Increase team productivity and help unify team members who prefer one over another by integrating the two platforms. 

Guidelines For Using Email and Slack

Since both applications are equally useful, you can start by outlining some clear guidelines regarding when to use Slack and email. This will avoid confusions and team collaboration will be rapidly enhanced.

Guidelines for Using Slack vs. Email

1. Purpose of Communication

Email: Reserved for formal, detailed, and external communications. It’s ideal for conveying important information that needs to be documented, such as project proposals, official updates, and sending messages that require a record or have legal/compliance implications.

Slack: Used for informal, real-time, and internal communications. It's best for quick updates, brainstorming, and ad hoc communication that are more fluid and require fast responses or ongoing dialogue.

2. Type of Message

Email:

• Official business communications (internal or external).
• Reports, contracts, or important documents that require attachments or formal formatting.
• Detailed instructions or long-form explanations that need to be clearly understood.
• Communications with external stakeholders, including clients, vendors, and partners.
• Messages requiring formal approval or action from recipients.

Slack: Quick questions or clarifications (e.g., "Can anyone help with this?").

• Team discussions, project coordination, and updates that are time-sensitive.
• Sharing quick thoughts, ideas, or links for immediate feedback.
• Informal announcements and internal communication (e.g., meeting reminders, updates).
• Collaborative conversations or feedback loops.

3. Level of Urgency

Email: Best for non-urgent or time-sensitive matters that can be handled over a longer period, such as proposals or contracts with deadlines. Use for communications that don’t need an immediate response but are still important.

Slack: Ideal for urgent issues that require a quick response or real-time interaction (e.g., system issues, project blockers). Slack messages are the right tool when you need instant messaging or clarification on tasks.

4. Documentation and Record-Keeping

Email: Use Email when communication needs to be archived or stored for record-keeping purposes. If there’s a need to track a thread for compliance, audit, or future reference, email will serve as your guarantee.

Slack: Its search features help with finding past discussions, but it’s not typically used for official record-keeping. Slack messages are good for workplace communication that doesn’t need to be retained long-term.

5. Length and Complexity of the Message

Email: Best for long-form messages, detailed explanations, and complex information that requires careful consideration or formatting. Includes messages with attachments, documents, or extensive information that needs to be read, referenced, or acted upon in a more formal setting.

Slack: Best for short messages, quick updates, or asynchronous communication that doesn't require in-depth explanation. Encourages back-and-forth conversations, so avoid using it for lengthy or complex details.

6. Tone and Formality

Email: Used when a professional or formal tone is required, especially for communicating with external clients, management, or partners. Essential for situations requiring clarity and politeness in tone.

Slack: Best for a casual tone or a conversational style. Suitable for fast, informal communication and fostering a collaborative environment.

7. Multi-Recipient vs. Direct Communication

Email: Use for group communications where multiple recipients need to be informed or involved, especially when that information needs to be detailed and clear.

Slack: Ideal for small group chats, internal communication or direct messages between team members or project groups.

In some cases, it will also be helpful to outline situations where using both tools in tandem may be appropriate, such as following up on slack channels with a formal email summary or decision. This creates a seamless communication flow, where each tool serves its intended purpose.

By creating these guidelines and encouraging consistent adherence, your team will spend less time debating which tool to use and more time focusing on the task at hand. Clear communication standards not only reduce confusion but also promote greater productivity, efficiency, and clarity across the board.

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Email and Slack: Get the Best of Both Worlds

To eliminate confusion, create clear internal guidelines that stipulate which tool to use for different types of messaging and forget about the “Slack vs Email debate.” You can unite both platforms with Gmelius, and explore some of the additional integrations that can help boost your team’s productivity. Check out all our features and integrations and learn how Gmelius is built to improve team communication and collaboration. Ready to get started? Sign up today!

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