- If your secondary account is hosted on Google Apps, you might need to allow less secure apps to enable sending and forwarding
- See details here
- Settings > Accounts and Import > Send mail as > Add another email address you own
- Enter info for secondary account
- Enable "Treat as an alias"
- If account is hosted on Google Apps with a custom domain
- SMTP Server: smtp.gmail.com
- Port: 465
- Username: full email of secondary account
- Password: secondary account password
- Select "Secured connection using SSL"
- Enter confirmation code sent to secondary account
- Settings > Labels > Create new label
- Name label after linked account
- Settings > Filters and Blocked Addresses > Create a new filter
- To: secondary email domain (e.g. "@domain.com")
- Click "Create filter with this search"
- Select "Apply the label", choose label created above
- Click "Create filter"
- Settings > Accounts and Import > When replying to a message
- Select "Reply from the same address the message was sent to"
- Settings > Forwarding and POP/IMAP > Add a forwarding address
- Use primary account email
- Click Next, Proceed
- Click forwarding confirmation link in primary account email
- Settings > Forwarding and POP/IMAP > Forwarding
- Select "Forward a copy of incoming mail to ..."
- Choose "mark copy as read"
- Click "Save Changes"
- Send email from your primary account to your secondary account, it should appear in your primary account's inbox
- Send email from your primary account as your secondary account to your primary account, it should appear in your primary account's inbox and should be from your secondary account's email address