MailChimp Campaign Archive adds a <code>[mailchimp_campaigns]</code> shortcode to WordPress. This shortcode lists your latest MailChimp email campaigns as an unordered list with links to view the HTML version of each email.
<h4>Usage</h4>
The only required parameter is <code>apikey</code> which you must generate from MailChimp: https://admin.mailchimp.com/account/api/
Example usage: <code>[mailchimp_campaigns apikey="xxxxxxxxxx" limit="10" order="ASC" link_text="title"]</code>
apikey 
Generated from https://admin.mailchimp.com/account/api/
limit 
Specify how many campaigns to list. Can be any integer between 1 and 1000.
offset 
If offset is non-negative, the archive list will start at that offset in the list. If offset is negative, the archive list will start that far from the end of the list. For example, set this to 10 to omit the first ten email campaigns from the list, or set it to -2 to omit every campaign that comes before the second to last campaign.
order 
Can be either ASC or DESC (ascending or descending)
link_text 
Specify where to get link text. Can be either “subject” or “title”
status 
Only show campaigns of a specific status. Can be: “sent”, “save”, “paused”, “schedule”, or “sending”
from_name 
Only show campaigns that have this “From Name”
from_email 
Only show campaigns that have this “Reply-to Email”
list_id 
Only show campaigns sent to this <a href="http://kb.mailchimp.com/article/how-can-i-find-my-list-id" rel="nofollow ugc">list ID.</a> The ID for a given list can be found by navigating to the Lists page, clicking the Gear drop down, and selecting List Settings and Unique ID.
folder_id 
Only show campaigns from this folder ID. The folder ID can be found in the “<code>fid</code>” parameter in the “Folder Archive Code”
organize_by 
Organize campaign list by date. Can be either “year” or “month”
heading_tag 
HTML element to use for month/year titles. Only needed if “organize_by” is set. Should be one of: <code>h1</code>, <code>h2</code>, <code>h3</code>, <code>h4</code>, <code>h5</code>, <code>h6</code>

MailChimp Campaign Archive

Adds a [mailchimp_campaigns] shortcode that lists your latest MailChimp email campaigns

Mailchimp

Use the Mailchimp List Subscribe plugin to quickly add a Mailchimp signup form block, widget, or shortcode to your WordPress site.
After installation, if you already have a Mailchimp account, you’ll log in with that account and then proceed to configure settings.
If you don’t have an account, you can create one directly in the plugin. After entering in all your personal details, you’ll need to activate your account via an email that will be sent to you. Once done, you’ll proceed to configure settings.
On the settings screen, you’ll select your Mailchimp list, choose merge fields and groups, and configure other options. Once done, you can now add the block, widget, or shortcode (<code>[mailchimpsf_form]</code>) to your site. Typically, installation and setup will take about 5-10 minutes, and absolutely everything can be done via the WordPress Setting GUI, with no file editing at all.
WordPress.com compatibility is limited to Business tier users only. <a href="https://mailchimp.com/help/ways-to-add-a-signup-form-in-wordpress/" rel="nofollow ugc">How to add a signup form if you have a WordPress.com site</a>.
<h3>Access Token Encryption</h3>
Starting in version 1.6.0, authentication has changed to use OAuth. As part of this process, we retrieve an access token that can be used to make API requests. To provide a high-level of security, this access token is encrypted before being stored in the WordPress database. In order to ensure this access token can be decrypted when used, the plugin relies on certain security constants that should remain unchanged.
With no additional configuration, we use the standard <code>LOGGED_IN_KEY</code> and <code>LOGGED_IN_SALT</code> constants that are normally set in your site’s <code>wp-config.php</code> file. Some sites make use of security plugins that rotate these constants on a periodic basis. When this happens, we won’t be able to decrypt the access token and you’ll need to reconnect your Mailchimp account to generate a new access token.
To prevent such issues, it is recommended to define two additional constants in your site’s <code>wp-config.php</code> file: <code>MAILCHIMP_SF_ENCRYPTION_KEY</code> and <code>MAILCHIMP_SF_ENCRYPTION_SALT</code>. These constants should consist of a combination of characters, preferably at least 32 characters long. Once set, these values should not be changed. For strong values, you can copy some of the values from <a href="https://api.wordpress.org/secret-key/1.1/salt/" rel="nofollow ugc">here</a> and use them. You’ll end up with additional code like the following in your <code>wp-config.php</code> file:
<pre><code>define( 'MAILCHIMP_SF_ENCRYPTION_KEY', 'put your unique phrase here' );
define( 'MAILCHIMP_SF_ENCRYPTION_SALT', 'put your unique phrase here' );
</code></pre>
If these constants are added after you’ve already authenticated with Mailchimp, you will need to reconnect your account. To avoid this, you can copy the values from <code>LOGGED_IN_KEY</code> and <code>LOGGED_IN_SALT</code> (if they exist) to <code>MAILCHIMP_SF_ENCRYPTION_KEY</code> and <code>MAILCHIMP_SF_ENCRYPTION_SALT</code> respectively.
<h3>Upgrading</h3>
If you are upgrading to version 1.2.1 and you used the widget in your sidebar previously, all you need to do is drag the <code>Mailchimp Widget</code> back into the sidebar, visit the Mailchimp settings page (which will have maintained your prior settings), click the “Update List” button, and you’re done!

Mailchimp List Subscribe Form

Add a Mailchimp signup form block, widget, or shortcode to your WordPress site.

MailChimp Campaign Archive vs Mailchimp List Subscribe Form